I converted a Taig mill to cnc, and used it to make a few injection moulds , I used a FET4 driver board from a company called stepperworld , I don't think they are available anymore , I used to run it from turbocnc , programing it in Gcode worked out on graph paper
I also made a mdf cnc router from plans from hobbycnc and used one of there stepper motor and board kits to run it, its a good one to start with as its so easy
The number of old cnc lathes available because the computers are broken is great, many older ones are stepper driven and can be converted very easily to run on a pc , ebay is a good place for old mills, routers and lathes that are broken due to electrical faults
I also have a Denford easyturn cnc lathe ( that I was given back in 1997 ) it did run from a tape player, but now its running as a fully auto lathe with bar feed, power chuck and tool changer, all run from an old pc running msdos and the turbocnc software
Most of the cheap controller boards work just as well as the more expensive ones