I checked for a small lathe but I decided to go just a little bit bigger to be less limited, I choose a 10x22 format and I'm happy with it but you know what... I already have part to do that is too large for my lathe
... But if I'll wait until I could buy the perfect lathe, I will only dream of having one all my life. Go with your budget and with what you will have to do most of the time.
Good luck in your quest
Ron