What material are you planning to use? My viv is similar dimensions (36Hx24Wx48L usable space) made of 1/2” and 3/4” plywood and it is really heavy! Just something to think about.
You may need more lights than you realize, and also mess around with it a lot so having the lighting accessible is a huge benefit. I have 3 basking lamps, 1 24” T5HO UVB and 2 36” T5HO flourecent lights.