bridgeport heidenhain replacement?

I'm finally going to get a first hand look at a 1987 Bridgeport CNC made in England. It is said to have servos and a Heidenhain control with Z axis driver in need of repair. We have a little X2 with Xylotex controller and MACH3, and we are contemplating putting this Bridgeport together with a similar system, but I'm not sure how big a bite we are taking here.

So, I need to look at the servo voltage and amperage ratings, but what else?? So I'm thinking that I might salvage the Heidenhain controls for someone else who might need them or a backup, and replace with a PC based control system and I'm looking for recommendations - both hardware/software as well as a time and cost estimate - please. Can I get this done for a few hundred dollars - say less than a grand, or is that a pipe dream?

We enjoy the X2, but it is really limited in capacity.

THANKS!! Chuck