I have exactly the same plan. I already have the steppers and driver board and I'm waiting for the drawer slides to come to be able to continue building. I've used free version of Mach3 to test the electronics and fiddled around with profili's 4-axis simulation. Heat will be controlled manually at first but I'm planning on controlling it through software eventually.
Your idea of making a designated screen for hotwire is excellent, I hope you are willing to share it.