Looking for some advice with first CNC purchase

So I'm in the process of buying a small machine shop from a guy that's retiring. He currently only runs manual equipment and I would like to get a CNC VMC and maybe lathe sometime in the first year. With my budget I'll probably end up with something from the mid 90's. With these machines using RS-232 ports for data, what's available to connect them to modern computers without these ports? Do people just keep old computers around for this? Is control hardware available or repairable for this vintage? What else should I inspect on a machine that may have 10-20,000 hours on it?

I have been using UG (NX) for modeling parts for a long time and plan on learning to use the CAM module for creating tool paths.

I found a 1994 Mazak VTC41 for $9500 that seems in good shape. It uses EIA control; should I expect any compatibility issues with NX CAM?

Thanks!