Hello, I might be getting a bp soon. I will be housing it in a rubbermaid tub. The tub is around 4 feet long, how long should the snake stay in that size? Or is that acceptable for life?(I doubt it)

Also, I read that temps should never fall below 80 on the cool side, and temps should always be 90-95 on the warm side. I also read that you should not use a heatlamp, then how do you reach these temps? UTHs, I know, but do you need 2? One on cool side and one on warm side? But then both temps are going to be 95...