The planters do have bottoms, with narrow slits to allow drainage. I bought a bunch from Riparium Supply and have begun giving them away since I kept growing fuzzy white mold (water level was much too high). I thought I'd try to use at least a few of them.

I found both pothos and philodendron available at NE Herp, stamped as difficult to kill, so I'll probably start there. Perhaps instead of a proper vining plant, I'll see if I can convince some of the moss they sell to attach to the background. This way, it won't be something I'll want to remove for cleaning, it won't be in an area where froggy can eat it by accident, and if it all dies off, I'll still have something covering the back. Always have a backup plan, I say.

This is pretty exciting. Thanks again for all the input.