Need ideas for my new WTF tank!!

[Sarosaurus]

I've got a pair of Whites Tree Frog frog's in a 20H tank. After my female decided to play escape artist, I have decided that I need to get something else that it's escape proof (more or less). I've ordered one of the Exo-Terra glass terrariums in 24x18x18. I'm thinking that will be big enough since it's going to be a smidgen bigger than the tank they are in now. I'm not quite sure how I want this tank set up though. I'm digging the idea of having some live plants in there, but not sure what the maintenance on them would be and if they pretty much take care of themselves if I set everything up right. I also wanted to put a waterfall in the tank, but I am not sure if that will work since I know those tanks don't have near the amount of silicone in them like the fish tanks do.

Any suggestions or ideas would be greatly appreciated!

I've got some time to gather the things I need before the tank arrives and there's no set deadline by when my frogs have to be in their homes.

Note: I've attached a picture of the current setup they are in. Not the greatest, but it's been working out thus far.