Interesting project. I have just about, bar a bit of tidying up, finished an electronics refresh on a Denford Orac. It came to me halfway through a project by the previous owner, meaning that he had stripped everything out and just started rebuilding. It uses straightforward steppers (driving ballscrews), simple microswitch limit switches, and a VFD driving the spindle motor. All easy stuff to drive. I spent quite a lot of time puzzling over what to put in.

I considered LinuxCNC but at that time the best interface card - didn't want to drive via a parallel port - was the Mesa ethernet card. However, every time I looked it only seemed to be available directly from the US and they always claimed to be out of stock. I'm told that this has now changed. I did consider the UC300 from CNCdrive as I use a couple of these already along with their UCCNC control software but their promised lathe-compatible update was still in development. It appeared not long after I ordered a PlanetCNC TNG board with their control software instead as this promised lathe support. It seems to do everything I might want except for constant surface speed. I understand that UCCNC does this as well.

There isn't a one-size-fits-all solution - depends on things like how comfortable you are with Linux and doing the software configuration to make it work in your system, whether you want a more-or-less turnkey system and suffer Windows, or whatever. Personally, I regret not having ordered the motion control hardware and software a month or so later than I did as I'm familiar with it on a mill and router but what I have seems to do what's needed - for me. Then there is the Acorn hardware and software, which seems to get good reports from its users. Kmotion/Kflop and its friends get good reports - but again, only from people who have made them work!

Good luck!