Well as I said my Novamill uses small 23 steppers at about 1.5 amps on the table drive, so they could work even if you have to keep the speed down. And you can get bigger higher torque modern steppers which are also size 23 so will be a mechanical replacement if you want to upgrade. For a psu see eBay item 330989848125 which I think is the one I bought. 23 quid plus shipping. They also have other voltages.