Hey, why don't you call a few local high schools or go to Techno Isel's website and see what you can find. I'm using a machine that looks identical to that in my classroom. Yes, I use EdgeCAM to generate the code, but there are plenty of more affordable code generators around. Techno Isel claims lifetime software support, so if you own the machine you should be able to get them to provide the software. I don't see why you'd want to replace the driver electronics or server motors--like you said it's built like a tank. It's nearly student proof.
Or better yet, sell it to me! I'll put it in the back of my classroom alongside the one I already have and we'll have two running.
Doug