Hello. I've been thinking about getting a new frog for the 20 gallon aquarium I have. (It is long rather then tall)

I've considered Red Eyed Tree Frogs but I'm starting to think maybe they wouldn't be too happy in a wide aquarium that they can't climb in.

I'm considering Poison Dart frogs but it has come to my attention that maybe they won't be the easier thing to sustain on crickets. (Hunting through my aquariums for small crickets will probably take a long time.) and that they are generally difficult to keep.

So, without totally abandoning any plans, now I investigate the possibility of a Firebelly toad. My current source of information is http://allaboutfrogs.org/info/mypets/firebellies.html but it seems a little inadequate. So, my questions:

1 How many can you keep in a 20 gallon? Do they also prefer a tall aquarium over a long one?

2 What temperature do they need? (I'd rather not have them trying to hibernate like my White's was.)

3 This person says chlorinated water is very dangerous, if I boil it for 12 minutes will it be safe?

4 Are they territorial like poison dart frogs?

5 Is there anything else I should know about them before I consider getting one? I hear they are durable.