That's a big lens on a small camera. I'd find one of the A6000 series cameras locally and test it out before you buy.  I don't know which lens adapters work with which APS-C bodies so check into that carefully, they're not all equal. Also, you probably know this already, but in case you don't, you'd be shooting an effective focal range of 225-1200 mm. Fun, but it's going to be a bitch to hold still when zoomed out! 

Pretty sure the forum downscales images. 

Hi, Am considering transition from A99 to mirrorless.  To start with, I want to get a A6700. Has anyone done this combination, and what are the issues aside, my interest is in wildlife ( birdings, whales and the ocassional African safari). The combination uses a Tamron 150-600mm lens (full frame) with a LA-EA5 adapter. cheers