Hi, this adapter is for Canon EOS mount lens to Sony E NEX mount camera, we checked the sony a 7iii camera mount is E mount , this adapter can fit it , but you can reconfirme it , thanks.  

Yes, it will fit any Sony e mount body, either full frame (a7..., a9...), or aps-c (like a6500, etc) 

This antenna will receive over the air (OTA) HD TV. I cant speak to your tv but I dropped cable 13 months ago. With Amazon prime you will receive a whole bunch of content. With HDTV you need a fair amount of band width to avoid buffering. You will probably also want an over the air digital video recorder (DVR) unless you are willing to put up with adds. I use Tablo. There is a whole bunch of minutia on how to get what you want but my house entertainment went from $250 down to $95 a month . Good Luck it is worth the savings don't pirate anything. Jim 

yes, i had no problems with infinity focus with this adapter. the only FD mount lens i use anymore with my sony is a vivitar 20mm, and i pretty much only shoot infinity focus with it. 

No, this adapter is for the older manual focus Minolta Rokkor MC and MD lenses. If you want to autofocus and aperture control you will need the Sony LA-EA4. (the lower cost Sony LA-EA3 will electronically connect A mount lenses but you will have to manually focus.)