Which Stepper Motor?

Hi, I am a newbie to this forum, in fact it is my first Thread, so please be gentle with me.

I am building my own CNC wood router, for cutting and shaping guitar bodies and other wooden parts, I have limited space in my man cave, so I have gone with an initial design with a work area of 800mm x 600mm using 16mm Linear Rails. My problem is I cannot decide if I should use NEMA 17's or NEMA 23 's, Stepper Motors, mainly because NEMA 23's appear a lot more expensive than NEMA 17's (I am retired on a Pension) The hardest wood I will be cutting will probably be Alder & Basswood for the bodies, I sometimes use Mahogany, Maple or Rosewood for Guitar Fingerboards, this usually involves very little heavy work

All advice would be gratefully appreciated, I hope I have provided enough information.

Regards.

Ray