I guess the only possible snag may be in running Fusion.....I'm not sure.
I good source, to me ,would be second hand Gaming Machines. They would have
good solid processors, lots of RAM, and a reasonable video card, abeit, a couple of years old.
Must be dozens on Ebay, or anywhere else people sell gear.Craigslist in the US?
PC's with parallel ports are rare these days. I would look at getting a Motion Control Card, so you don't need to go that way.