That should be relatively easy to convert to a different controller.

Regarding the VFD, from memory, DCM is normally a 0V which I would expected to connect to pin 14. However you really need to find a manual for the VFD. If you were to go for a CNCdrive UC controller, I'd probably suggest the UC400 along with a suitable breakout board.
You'll most likely need to add an additional power supply to power the controller and breakout board.