Thanks guys! :)

@Mustang5 - we picked him up from a shop called Arizona Reptile Center. My husband visited 3 Herp stores in our area (didn't bother with the "big box" stores) and the people at ARC were the friendliest and most knowledgeable, and their store was the most specialized. Every customer in there had only good things to say, and the snakes were healthy and looked good - I got to hold a couple Balls, which was really the tipping point from "okay these aren't so bad" to "hey this is kind of awesome!" and we picked up the whole starter kit at the same time. :) I'm looking forward to him coming out of his hole and being my friend!

@frostysBP - DH is a workshop enthusiast, his dad was in the business of building houses for many years and passed on that hands-on DIY spirit and know-how. If you'll believe it, we've almost got the Carpet enclosure finished - the base is actually a repurposed TV Console. I'm not a maker like him (he's into power-tools, I'm into paint) so I couldn't really tell you all the details, but we've layered the inside with some kind of laminate sheeting, and he's reinforced the sole remaining drawer as a hidey-hole with a hole cut over it in the floor of the enclosure for the snake to move in and out of if it likes. I've played 20 Questions with him to make sure it's snake-safe and snake-proof, and I'm assured that nothing is going to be getting out of this thing, and there's going to be good light and ventilation. I trust he's done his homework... he's been a snake-lover since he was a kid (his dad is not herp-friendly, so he never got to own a snake growing up).