Help: choose between two Optimum / Quantum lathes

Hello,

I'm new to this forum ( and new to machining, in general ). I have one
question: don't know which lathe should I buy, Optimum 180x300 or
Quantum 210x400 ( not 210x400 Vario, it's too expensive ).
I need precision first of all. I need to make some sort of discs that
would hold miniature ball bearings on the outside and also some small
shafts that would go in the inner part of those small ball bearings.
Like in miniature brushless motors.
If someone has already bought / tried one of those lathes, please
reply me which one is better. Any advise really appreciated.
I also plan to convert the lathe to CNC. Has anyone tried this on one
of these models?