Nema 23 for the X-Y is fine. With CP you don't really save any money with the 23. The small Nema 34 are OK too and they will stick out less.
Nema 23
https://www.teknic.com/model-info/CP..._voltage=75VDC
If you want to go to Nema 34 for the X and Y.
https://www.teknic.com/model-info/CP..._voltage=75VDC
For the Z.
https://www.teknic.com/model-info/CP..._voltage=75VDC