gethin

I agree with shooting for the Sony Alpha A1 and adapting F mount lenses until you grow native E mount. Alpha A1 seems to do pretty good at everything and has 8K video and improved DR over what you have.
Canon just doesn't have enough native RF lenses yet and since you don't have any EF lenses, it really doesn't make much sense to buy anything from Canon.

It's not the camera I'd be concerned about, it's the lenses and I think it may be time to dump F mount.
I'd be tempted to get a Sony A1 which seems a good fit for your high-resolution needs plus cutting edge video specs.
Then I'd be tempted to put all the Nikon lenses on eBay 🙂
Start investing in the native E-mount Sigma range.

There are a number of F mount to E mount adapters with full autofocus available that would give you a path to Sony without sacrificing the lens collection.
Similarly, there are also E to Z mount adapters so that you could then share E mount lenses with your Z6.
That way you could use the budget to really push the boat out and get a Sony A1 to give you a bump that you are after in video (8K I'm guessing would be a client pleaser from a marketing perspective) and it also does ProResRAW but also you'd get a big bump in stills with its 50mp sensor.
You could then also get that Sigma 105mm in E mount and be able to use it natively on the A1 but also with the adapter on the Z6.
I think if you went this route then you'd get the immediate bump that you are looking for but also be able to hedge against the release of the Z9 as I'm guessing Nikon is really where your heart is and you're not yet ready to fully abandon ship just yet.
Far cheaper too as it would be half your budget.

OK, I’ll play…
Nikon Z7ii for stills and a Z6ii for video with Atomos recorder.
Or sell the lot and go for a Panasonic S1H based system 😍

Yep I thought about that but used z7s are still about $3k in Aus, I saw a used a7rii yesterday for $1000!  
I figure I can get an autofocus lens adaptor. And still be ahead. But yes matching the colours might be interesting.  I probably should find some RAWS and footage to play with before I jump in.   

Primarily for stills? Why not a Z7? Keeps you in the same ecosystem! That's the smart practical choice.
  
Oh! That's crazy cheap. 
But then you'll have the problems of the a7 mk2 series: overheating, short battery life, etc

Just as a comparison:
I regularly do Portrait-Photography with my 5D Classic from 2005 and make videos with the BMCC 2.5k from 2012. Both cameras are able to deliver stunning images/videos.
I own both a Pocket 4K and a 5D mkIII, but I don´t feel I can´t get good footage, when using the older devices. Sure, the new ones offer some nice things, but they aren´t nessesary all the time.
So I think a a7rii  form 2015 is a great camera. If you can buy one for a great price and you like the image you get, go for it.

I've easily shot 50k images with the a7r2 and its still my favorite of all the Sony sensors, eventually I'll probably own another as a landscape/backup camera. I'd love it if they did a faster version of the 42mp sensor for the next a7IV. Even at about $900 or so used, the a7r2 is a bargain for the IQ. But if I were in your shoes, I'd probably stretch that for a used Z7 just for the easy compatibility with lenses/batteries and same colors if the budget allows.
Cheers
Chris

Saw it from FB post, really curious about the price of it.
possible up to 1000fps in 30 or 90s 

Agree! I don't really fancy much of what's on offer.
I'd think about getting a video only cam, but the blackmagic is M/3 or bloody eos mount.  The z-cam has similar caveats.  AN d besides I dont mind being pampered now and then with an auto mode that actually works. Or Ibis. Or autofocus. Oy vey! I think I better think it out again
 
 

yep i was saying this was nikon's last attempt to keep me. HAving said that I'm editing some footage at the mo, and it's lovely, and very easy to work with, but there is too much that is amateurish with these cameras.  If they'd given me full frame 60p I might even have hung around in 8bit. But no 10 bit internal? get futtocky fucked. 
And "planned for february": weasels. THe promised external raw was a mess. Nope, bugger 'em
 

I don't know what's going on here but it's not like they have a cinema line to protect...
Panasonic could have that excuse, but don't use it and just have the somewhat iffy AF issue.
Canon are full of controversy.
Sony have been criticised by only having 12mp for the A7S3 but it looks like when the A74 arrives, now that Sony have improved ergos, menus and colour, they are just going to walk over the whole lot.
And I am no Sony fan but the electronics giant is stomping on the more established camera companies.
It's like they all want to commit financial suicide and close their doors.
Or are we some tiny minority that sees this, but 99% of the rest of the world don't give a shit and just hand over cash to any brand they recognise the name of or the fella in the shop sells them?
I think if the answer to my question above is "no, the 4k 60p when it comes is 8 bit", then I'm on a course to see if the S5 will perform in ALL the roles I'd need it to.
More than a bit pissed off with all the camera companies right now. Every single one cripples in some degree or another everything they are putting out for no apparent reason other than they can. It's just fucking weird! 🙄

Um yeah. I'm now going to sell all my Nikon gear.
Colossally disappointing, especially have the RAW remain a paid upgrade and no 10-bit. Hell they couldn't even remove the goddamn 30 minute time limit.  The fact this camera has NO VIDEO IMPROVMENT AT LAUNCH is tone deaf idiocy. 
Hell the 4K 60p being added later as a firmware upgrade and not being able to record it externally just feels like a final kick in the teeth.

No N-log internal
No 10bit internal 
No 6k raw (full sensor readout)
Paid raw update that too line skipped 4k
DISAPPOINTING😔
I don't think they have taken any feedback from video users.
 
 

someone in the nikonrumors comments said the sensor can only do 40hz in full frame.  Not sure if this is true but if so, rules out 4k 60 FF.  I agree, they shouldn't give it the ii moniker if its a minor update. Urgh! 

I’ve never tried the Rokkor’s, so thanks for bringing that to my attention. I’m a sucker for imperfect vintage lenses, it’s like a crack addiction.
Im with you on the Edge, not too bothered  about that lens. I don’t find that effect useful. 
Check out the Sol45, that thing is nuts. Got some work to share soon using that and other Lensbaby’s. . 
 

For Helios 44-2 just flip rear element (rear glass inverted) and you get a heavy instant swirly bokeh!! 

Exactly. It shouldn’t be. My Bolex from the 60s has an internal ND slot built in... Takes two seconds to drop in a filter. The cost and development required wouldn’t give companies a high enough ROI... So nobody does it.
I think I remember someone developing a internal ND for the original black magic pocket. If I remember correctly, it took a few minutes to install. 

I find in practice it is less convenient then a screw on fixed ND. It really only make sense for lenses that you can’t screw a ND on the front of the lens.
 

I think @IronFilm is right for narrative indie filmmakers. I can't speak for wedding/corporate/doc people, who may need more mobility, AF, and less rigging. I think even music videos tend to require more mobility than narrative.
In my experience, even the worst Blackmagic camera, the 2.5k EF mount, was preferable over the Panasonic and Sony mirrorless that I also used back in ~2015. The only thing comparable was 5d3 raw, which was unreliable and an even bigger PITA to use (and also more expensive, incidentally).
That said, obviously photo/video hybrids are a different class which does exclude things like the Pocket, or GoPros, etc, so it's a useful categorization.

I think the entire reason why people got into using Canon DSLRs (and Panasonic GH series, and Sony NEX, etc) for low budget filmmaking is because they were extremely affordable. Not because they could do stills too. 

If we'd had even just merely an OG BMPCC / Z Cam E1 / Terra 4K back in 2008/2009 then I expect very few people would have purchased the likes of a GH1/T2i/NEX-5/etc specifically to film with. 

Of course now we're spoiled with many more advancements: P6K / E2 series / Mavo / etc

Could use a price limit as the definition to be included or not? Instead of if it is or isn't a hybrid camera. 
Could even have two categories, such as: sub $5K (so would include the likes of a Z Cam E2-F6 alongside the Panasonic S1H) and sub $2K (E2 M4 vs P4K vs GH5 vs S1 vs Z6 etc)

Whilst the hope is that Canon will fix this properly, the probe app (which we made after the temperature monitoring one) can be used to restore the majority of user preferences, not a big deal to get it to chain them into one big faux preset to send back to the camera.

If there was a way to feed the correct time and date, and saved settings back to the camera that would be niiiiiiiiicer

Apart from the artificial crippling, the consensus is the camera doesn’t actually overheat? What voodoo is in there that the S1H doesn’t have? (which needs a huge vent). 
Thing is, if Canon didn’t do this I would of been a customer of 2 bodies and a bunch of RF lenses. Plus I would of likely picked up an RF cine cam in the future. Just doesn’t make much business sense to me.