Ppl tend to way over think about setting up an enclosure around here..don't drive your self crazy,OP.
you will prob have to try a few different watt bulbs,different things to set humidity etc.. To get right temps and humidity..Make sure u set your heat mat with a thermostat and monitor it with a thermometer. Get a hygrometer,I use a regular analog one. Set a large water bowl in the middle of the tank heat dome on the hot side as well... Mist if needed,or keep a very wet thick rag/s covering most all the top of the screen. Depending on substrate add some sphagnum moss if needed. There are ways I have found easy to keep humidity up.yes , It's really that simple.i keep a sticker thermometer on the hot side as well,which I never even really look at. I use the same bulbs all the time and use the same set up every time,nothing changes,cause it works.
if I told you the set ups that people I know have for there snakes and BPs,you'd prob see the basics are fine and no need to drive your self crazy.
this is basically my set up. Simple and easy and efficient. I have no issues.