After trying to use Mach3, I decided that the 2012 Laser DSP controller from LightObject.com would be a much better solution. However, I wanted to keep the parallel port input of the laser control board used for Mach3, incase I needed to use Mach3 for a custom purpose in the future.
The solution was to wire everything from the Laser DSP into a parallel connector, and run a parallel cable to the laser control board. This also reduced the amount of re-wiring to practically nothing.
Below is the DSP with the parallel connector mounted to a bracket.
In order to run the USB connector from the DSP computer, there would be a cable dangling out the back of the laser. This is not a clean setup, so I created a panel mount USB A to B connector. That way I can run a USB cable from the DSP to the inside panel mount connector, and then connect a seperate USB cable between the computer and the laser.