If you are getting a juvie snake here is what I would reccommend. I only have one snake and she does great in this setup.
-One 16 quart iris tub with a locking lid. There is no way for her to get out of this.
-Aspen bedding as substrate.
-A UTH taped (foil tape, in case you want to switch to a rack later and remove it) to one side on the bottom of the OUTSIDE of the tub.
-A thermostat (or dimmer) to control the heat of the UTH
-A probe thermometer or heat gun to measure temps
-One appropriately sized hide. (some reccommend two but i keep her tub in a pretty dark place to make her feel more secure)
-Water bowl
-Fake plant decoration if you so choose

Tubs are great. Even if you only have one snake. Cleaning out an aquarium is ridiculously hard compared to tubs. Tubs hold in humidity very well and you will almost never have to mist. Also, they are super light and portable. I don't think I will ever go back!

Tub with the lid

Tub without the lid

Pissed snake because I woke her up!