"Best" White's tree frog tank water setup and temperature control?

[Shontovia]

Thank you! I'm not worried about the actual plants and climbing areas, hiding scenario and whatnot. I always have fun with that, I'll do them justice. So 3 would be happy in a 40? And a decent enough water dish to soak in and not evaporate between refills (once or twice a day) would be good?

For financial reasons I'll probably start with one, but I want 3. If I find a good deal with breeders like LLLReptile or at a show I'll get a trio from the start so things are easier but we'll see. As long as they're all similar size they shouldn't be aggressive, I'm assuming? I've never heard any horror stories unless one could fit in the others' mouth.

Also, your habitat is very nice!