What is adequate for a stepper motor?

I'm planning to CNC my shopmaster when it arrives as well as a
mill/drill I picked up. In my parts bin I have a few double stack
Nema 23's which are supposedly 100 ozin, 1 triple stack 23 which is
150 ozin, and a couple of little 17's. I suspect that none of these
are adequate (well, for the Z direction of the mill/drill if I
attached to the current fine feed wheel, even the little 17's would
probably do OK actually). So I'm looking for some 34's (since that
what will bolt to the Shopmaster anyhow) and I've found some double
stack 34's Superior Electric 300 ozin. I'm planning on using a 63
volt supply. Would these be adequate for both applications?

I'm not bent on ultra fast rapids, but I don't want it to be turtle
slow either. I could get the motors for about $60 each which I'm
guessing is a half decent price.

Any comments?

Thanks,
-Chris