Search:

MCB's cost like £5 each and glass fuses like 50p so it's crazy not to use them IMO.
In my control boxes, I fit 3 x MCB's one for the Main toroidal PSU, VFD, and low voltage PSU's, the drives each...

I would go no less than 48v.
48V 800w will do it easily.

Generic 4 axis kits normally come with 2x 36V 350w supplies so the supply I suggest above is plenty :)
(36v is usually dissapointing).