I know the kind of enclosure your talking about. ive seen them lots of times. I have pretty much the same kind of enclosure set up as everyone else except that i use cage carpet or astro terf i keep 2-3 pieces per enclosure so while one is being cleaned i can put another in. as far as selves go im not sure how you could do that but i bought those bendable branches and drift wood and made almost like a little net my babies can lay on or crawl through and they seem to like it. you know about those selves if you get a piece of wood as wide as one end of the enclosure, and a few smaller pieces you could put selves in a staggered pattern cover the whole thing in say the cage carpet(to cover any rough edges) you could remove it for cleaning.add a few vines etc for security and voila just make ure its well supported so it doesnt tip over. hope that gives you some insight or creative ideas