I want to thank everyone again for your advice a few weeks back. After a lot of thought, I ended up taking Dartboard's advice and now I have both the Terribilis and Azureus. After a couple of weeks, heres the breakdown:
So far, there have been ups and downs. A local pet store had 2 P. Terribilis for sale so I went with my gut and bought them. Let me start by saying they are my absolute favorite among my dart frogs. Bolder than I even expected. Absolutely no regrets about buying them. My only issue is whether they are in fact Terribilis or if they were maybe mislabeled and are actually Bicolor. I don't know their ages at all, but they are rather small and are a bronze color. Either way, great frogs.
The issue, unfortunately, is with the Azureus. I realize now what everyone was saying about the group frog issue. I didn't want a group per se, but I wanted pairs (not necessarily sexed) of each species. Well, my one Azureus, a full sized female, does not get along with her tankmate (unsexed). I even moved her (temporarily = less than 24 hours) into the tank with the Terribilis, assuming she'd back off. After she attacked them, I was forced to move her again. She's now set up in a 20 gallon by herself.
Basically, the Terribilis are great. As for the Azureus, I should have waited until I could comfortably afford a sexed pair of Azureus before I bought them. But I guess that's why I'm on the beginners' forum.