If you set up a Joe's CNC, them I'm pretty sure you can handle doing your own controller I am kind of doing what you are doing, except I am using a bunch of my "yard sale" stuff I have laying around from other projects and picked up some used Avid Nema 34 steppers on ebay. My controller will most likely look like a rats nest, but can get up and running for about half the money of doing plug and play. There really should be no difference in accuracy. I will be giving up some speed and power since I won't have the perfect match of drivers and power supply, but can swap those easy enough later on. Like others have said. I think as long as you are ok doing the work, its much better value!