Hello, got myself a Sony a6000 and love it. However, I do not like the lack of fast native E mount primes and want to look at other options. I like the Sigma 18-35 mm f/1.8 lens which they make for Canon EF, Sony A mount, Nikon and Sigma. I need auto focus for my still photography as well, so the Nikon option will not work. Which mount/adapter combination would you guys choose to get the Sigma lens going on the a6000 with descent AF performance? I am in between Canon and Sony. Will AF work good enough??? Thanks a bunch!