I want the whole top to be a glass panel that lifts up on a hinge. I'm thinking of lining it with garden pond liner. I plan on having it 12" deep and maybe keeping fire belly toads in it. I like your "bin" Idea I think that could work for the water needed to keep the toads. I could cut a hole in the bottom drop in the bin and be able to remove it for cleaning. It would be mostly moss, but aren't there other options for plants at that height like small ferns? For the lighting I'm think flourescent grow lights along the sides. I'm planning on framing the glass top in 4-6 inches and that would be enough to hide the fixtures.
Any suggestions and comments are welcome!