On the Z-axis motor, I have a G0704 and the 570 oz-in does fine, but if I were to do it again I'd probably go with the NEMA 34.
I can't say if the PM25 would use the same ballscrews or not.
As far as electronics, you have options.
First is parallel port control where the parallel port of the PC connects to a breakout board (C10 or other) and the motor driver connect to the BOB.
A smoothstepper or similar device would connect to the PC via USB or ethernet. I would also connect to a BOB and then the BOB connects to the motors.