My opinion,

I just ordered some from Repti-Racks. I ordered 47x23x14. I ordered 14 tall more for myself to have more room when cleaning, feeding, and playing.

Just remeber that if you get built in heat and then cut the cage down with a divider that it is a good possibility that the uth will cover the entire floor area of the part you want to use. You may want to opt out of paying for heat and install flex watt yourself so you can make it a larger uth as needed. Otherwise paying for the uth will be a waste. I also ordered the 47 long because I want a few more large bloods and maybe a boa. Thats really long for a ball, I would save some money and get a 36 inch.