Nice looking machine. Even if it is missing a number of parts.
Some questions to ponder:
1) Acrylic quality and/or suitability?
My limited experience with acrylic is that it is rather brittle and over time acrylic parts "shatter". Perhaps your acrylic is better quality but that has been my experience.
2) Machine rigidity? Acrylic is not a very "stiff" material.
The main acrylic upright supports may need to stiffened. One way (not the only way) is to make them thicker.
Recommend the perfect axis stepper motor with rear shaft and driver, nema17, 59Ncm, 1.8 degree.
Stepper motor:
https://www.motiongoo.com/index.php?route=product/product&path=59_77&product_id=55
Driver:
https://www.motiongoo.com/index.php?route=product/product&path=59_95&product_id=228