Re: Oophaga pumilio
I don't think they're really that hard to care for as long as they're captive bred, it's just the breeding that's tricky. Also, the morphs don't really differ in difficulty, just color and origin. You're best off going for something cheap and CB. Of course, that's just what I've extrapolated from other people's stories, considering I've never kept them.
People have made paludariums for frogs and fish, there are a lot of good construction threads on that.
If I were you, I'd keep a male and a female, not two males. That way you get eggs and no aggression. In that case you could keep the pair in a ten gallon.
Pumilio tadpoles are obligatory egg feeders, which means they need to eat their mother's infertile food eggs to survive. The adults would take melanogasters. Depending on the morph of pumilio, paprika would help intensify the red color. Still, that's not a priority like the vitamins, minerals, and calcium are. Traditionally they're fed daily, but I feed a lot and let the extra be eaten during the next few days. Kind of a necessity since they don't come running to eat.
Neither the plants nor the frogs need UVB, it's really a waste of money.