Your existing motors should work fine...as long as they are still operational. The based on the photo you posted of the motor, Gecko G201X drives will work. A power supply in the 36-48V range and a PMDX-126 BOB should finish it off. To figure your power supply current, add up the current draw on the three motors and take 2/3 of that. Since the Z is usually smaller than the X and Y, I usually just add the X and Y and go with that. It's always worked. If your motors are gear or belt reduced and you need fairly high RPM, you might want to stay on the high side on the voltage range.