Hi sorry about your beardie. For 22" tall it would be fine for whites, but for arboreal herps I personally prefer at least 24 inches height or more. Fire-bellies would make a better display, since whites are nocturnal but fire-bellies are active both day and night. You could put so many in there that you'd always see some but they'd probably breed, so you'd have to be up for raising tadpoles. Dart frogs also would be good and they're pretty low maintenance, just design a nice planted set up and you'll never need to clean for years, just need to set up a few fruit flies cultures, but with any amphibian you'll need to keep and gutload insects anyway. I'd suggest getting a few books to look at different species and see what might appeal to you best, there's so many frogs to choose from