Ooh, thanks for mentioning it! Yeah, I'm drawing little diagrams in my sketchbook right now to try to figure out the size of the shelves I would want, to try to maximize the indoor space but give him room to climb. His old enclosure was like this with ramps and stuff, but also some branches, and I'm trying to remember how they were set up and how I could improve on the old one. Once I figure that out, I will try contacting them with my specifications and asking for a quote. I also did find a seller on Etsy who would make me a 4' x 4' x 2' one with shelves, but that shorter depth could make it difficult for me to make efficient shelves/levels.
The legislation is unfortunate for me budget-wise, but I will hopefully be able to get a nice quality cage that I can use for decades, so am kind of looking forward to setting up something nice for my iguana.