All night heat should be supplied by a ceramic heat emitter, nothing that has any type of light. Also, a 40 breeder is a bit on the small side. You should look for something closer to a 48"x18" or 48"x24". Can you get the proper temps in a 40 breeder, yes. can you get the proper temp gradient, absolutely not. The gradient is more important then being able to just get the right temps in a tiny area. Uro's are not as small as a gecko, and need to be able to regulate their body temps, so the gradient is very important.

Hope that helps.