I'd personally recommend the T12 with the extra height. Boas and corn snakes will use all the space you give them -- I have a young Sonoran in a 4'x2'x2' right now, and she enjoys climbing up to her basking shelf 7.5-8" inches under the RHP. If you want to build climbing space for your snakes, it's important to remember that you lose 7" of climbing height when using an RHP (given an 1" think RHP and keeping objects at least 6" away from the lens), so having a taller enclosure gives you more opportunity on this front. Taller enclosures are also easier to reach in and clean, which is another plus.
While I prefer sliding doors with locks, I agree that a corn snake could easily wiggle its way out between them. I don't think you're missing anything else from your list. If the room you plan on putting the enclosure in is busy, do make sure you add plenty of hides and cover. Good luck!
Reply With Quote