I think the garage cabinets made by Rubbermaid, Black n Decker, etc. are great for this sort of thing. I used the wall-mount-style cabinet to create my current crestie enclusure, but there are two larger sizes, with the largest going generally for a bit under $70. Replace some portion of the door plastic with craft mesh or galvanized steel mesh or even plastic garden mesh, set up the shelves and dividers the way you like them, even split the doors height-wise if you want, they're very customizable if you take a creative approach. You can have small enclosures for the full height of one side and one or two taller ones on the other side, or whatever.