Paul,
   It sounds like the "Universal PWM Servo Controller"
("http://pico-systems.com/univpwm.html" $250.00) might work with your
amplifiers and it interfaces with the computers parallel port. He also
mentioned adding encoders for positioning.

--
Blake C. Lewis

I will give him a call tommorrow. I need some more answers.
I notice he is in Kirkwood Mo. Is he anywhere near you?