Your link actually got me looking at more and more fancy models, and I really like the nautical porthole kind now (~$50), as long as it's not too big for a tank. I'm a little crazy, I know.
I like ferns, so that can work. When it comes to keeping the heat in at night, because of the tank size, would you need to go with a ceramic heater or would one be able to incorporate a shelter much like their natural termite mounds which would keep them warm at night? I know one reason that works in the wild is because of the size of the mounds, so I'm not optimistic about replicating that in limited space.
Great, that's one of the things I was worried about: the soil needing to be replaced with all the plants in it. I was wondering if there was a way for it to keep itself maintained in a tank. Because I just recently watched some things on an aquarium doing just that. The person running the tank claimed to never vacuum his substrate.