I have had the older Atlas belt drive and it had speeds and feeds. I have tried Sherline and wasn't that impressed. I have had Unimate it had feed but no threading capabilities unless you bought attachments for each thread you wanted to turn. Ended up with a 36 inch bed Grizzly Gunsmiths lathe and never looked back. Now this may be large for your needs but look at the smaller bench top lathes by Grizzly. Their lathes come with quite a few attachments and their support is great. I live in Canada and my lathe was delivered to my door. The truck had a lift gate and the driver a pump truck. Together it was in the garage in short order. Check them out.
http://www.grizzly.com/products/cate...60000%7C700000
The 7 by 12 you will have to change gears to get your different feeds. The first quick change starts at the 9 by 19 size. The GO516 combo give you lathe and mill on the same machine but you will have to change gears for the lathe feeds. Look at the accessories that are included.
Dennis