Honestly, I think the guys at CNC zone get a lot more involved in DIY CNC stuff. Good info over there on that. I honestly do not know what one would want to use steppers. Maybe that is just easier and offers open loop configuration. I would think, if it was worth messing with, it would be worth doing right.
here is a BUNCH of CNC controlled equipment for sale right now. Even if you bought old, the iron is worth something and you have a platform to work from. What really dates machines is the electronics. may just upgrade a quality machine and go. We were itching to upgrade our old tree CNC a while back and go PC based but did not have the time to mess with it. Time is money in this game.