H iPeter,

For the Stepper Motors:

NEMA23 570oz/in 5A 1/4” Dual Shaft Stepper Motor (KL23H2100-50-4BM)
Those look good to me and others have used them. Expect maybe 400RPM with a 48V supply.

Unregulated Linear 45VDC/13A Toroidal PSU (KL-4513) with 5VDC
I prefer regulated switching supplies. They are regulated and lower cost.

48V Power Supply - 15A Single Output, Item #HF700W-S-48
This should work well but is somewhat overkill and expensive. Consider a Mean Well 350W supply for ~ $40

https://www.digikey.com/product-deta...350-ND/7705033