I use the same type of tank that Katie uses and it has been absolutely wonderful. Mine is a little larger than what you might need with only one frog, but my guys just love it and the extra tall space. It gives them plenty of room to jump down from vines and we've never had a problem with them getting to the top of the tank (unless they've crawled up there to sleep).
I bought mine at PetSmart, but I did look on Amazon. They had good pricing available. I found a similar tank, but different brand and it's on sale for half off right now! So that might be a really good deal to get right now!
http://www.amazon.com/Zoo-NT-3-Natur...ref=pd_sbs_k_4