PVC cages are nice because they are already enclosed on all sides but the front for security, nice and light, not breakable and hold heat/humidity excellent. There's tons of options, Vision, Monster Cages, the Animal Plastics t8 seems to be very popular for ball pythons, I have boaphile cages myself but lots of companies making them with various styles and options. Instead of heat lamps which are kind of dangerous, not so controllable and suck humidity you can use under tank heating if your room is warm or in a cooler spot a radiant heat panel works great. I spend about $300 per 3 foot cage and $400/4, but that's with both types of heating, upgraded locks, bells and whistles lol and seems pretty reasonable to me for a great looking cage that will last my snake for life.
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Also yes you can use CHE in an enclosed fixture, just buy one that specifies it's safe for ceramic. I've been using them over a decade always in enclosed domes.