Thanks for the replies
Ive looked at the motors and drivers on the zapp site they look like they will do the job, i will still be doing the knee rather than the quill, but with reduction set up with pulleys. Ill have to save up a bit though 3 motors and 3 controllers will be pushing my budget a bit (along with brackets, plugs, sockets, wiring, enclosure box, etc). This hobby can get expensive very quick.
Also can i drive the PM2278 from a 220v three phase supply from an inverter