I ended up going with these with a very similar setup
http://kitchenrestaurantstore.com/winco-alxp-1826-sheet-full-size-gauge-alumi-p-199608.html
I have cages suspended in 2' by 4' wire shelving. The cages are only about 14" deep though, so I use two of the 18" by 26" sheet pans and they work...