This is a great project. I have a uPrint which I am contemplating doing similar things to now. The only difference at the moment is I want to add water-cooled hotend and dual extruder, to increase the capabilities somewhat. I am thinking of taking out one of the chamber heaters and using that space to stick the radiator, putting the fan running into the chamber afterwards, still need to do a fair bit of experimentation with that part of it yet.
If you need any help with the programming of the firmware, I'd be happy to collaborate when I get to that point. I was also wanting to keep the original LCD display and buttons, but I haven't given this enough consideration yet.
Good work!