What would be the diameter of unsupported rails? What will you cut?
Nema17 are on the small side.
I had nema17 on my first cnc with 5/16 threaded rod, (1.4333mm pitch) but as soon as I upgraded to T8, the steppers were stalling more often.
Try to find a small nema23 stepper like this one: https://www.omc-stepperonline.com/hy...rice&order=ASC
A cheap TB6600 drive is more than enough to power it.