http://www.dendroboard.com/forum/care-sheets/14619-dendrobates-auratus-novice.html
A caresheet to look at.
You dont need a tall viv for auratus. You should have more horizontal space for auratus. You need to build a horizontal landscape. If you search this forum for member vivarium, you can find amazing build for auratus. 30x 13x12 is about a 20 gallon tank and should hold a pair.
Riccia and java moss would look amazing especially for auratus. I recommend using hydroton balls(clay Balls) instead a false bottom or you can go either way. Up to you.