most of my ball pythons can be house in 32, but the big girls need the 41. BRB will need something bigger than a 41 more than likely. I think ours are in 74 or some where around there.
Looks like I will get the Iris CB70. I like the fact they are made with thicker plastic. If the BRB out grows the rack I can always get a larger home for it.
Im going to start with a 4 container for now. I really don't see myself ever needing more than that.