For myself,one "must have" on a lathe is approx 1 3/8 bore through the spindle.This is the size to take a 5C collet draw bar.It allows a long bar or barrel to go through the headstock.We also have a spider(a cap with centering screws,like a chuck) on the back end of the spindle,so both ends of a barrel can be indicated to no run out.
For some reason ,most all of the import lathes that come pretty close to the size/features I prefer are made as gap bed lathes.Maybe that is OK,but it turns me off.I would prefer one made with a solid bed.
It has been a while since I looked,but it seems like the brand I came up with that looked like a real nice lathe was a Sharp,but it was about $12k.
For myself,I would likely look till I found a good,sound,not-worn-out Bridgeport.While thereare definite advantages to the variable drive head,the step pulley heads are single phase,and probably more long term durable.
How hard will you work them?10 hours of light duty a month ,and decent care,it does not take a lot of machine to last a long time.
But,it takes a certain level of quality to single point nice,accurate threads,etc.