Hi, Check and see if the drives can handle step (pulse) and direction. If so, no problem. You have numerous options. Here is a picture of Industry Controls motion board. It has step and direction and differential. The add on board available in about a month will operate +/- 10V. Encoder feed back is already built in and it has closed position loop built in. It uses a USB and not a parallel port. By using a 6" or shorter cable and keeping the USB board next to the PC, noise is controlled. The USB board then converts the signal through RS485 cables to the motion control board.
This board has been tested to transmit 200 feet while putting 18V AC on the ground of the machine without failure. It also has (18) Inputs and (8) 24Vdc relay outputs. There is a 50 pin header for an Opto 22. This can add more I/O at will.
I hope this helps