Have you considered LED strips?
It would cost quite a bit more, but would make wiring and construction easier.
You should be able to get something like these (UK store):
http://www.rapidonline.com/Electronic-Components/330mm-Rigid-LED-Strips-12V-8x-LEDs-524998
You would 7 this size so these ones would work out at about $50, but you can probably find cheaper.
It would cost quite a bit more, but would make wiring and construction easier.
You should be able to get something like these (UK store):
http://www.rapidonline.com/Electronic-Components/330mm-Rigid-LED-Strips-12V-8x-LEDs-524998
You would 7 this size so these ones would work out at about $50, but you can probably find cheaper.