Yeah the doctors I spoke to said that sunbeds can do something in the way to help, but because it is a mix of all sorts of lights, it wont be a significant one.
The stuff I had was concentrted UV exposure for up to 5 minutes towards the end of my treatment and it has made it a lot easier to manage to simple exposure to summer sun...just not so easy at the moment as we approach Christmas !!!
Anyway cant wait for the summer to start, going to be out in it A LOT.
Good luck to you though mate, hope you find something that might help with the un-curable