Have you looked at Pygmy Angels? Also known as Cherub Angels. I just recently added one to my tank and he's AWESOME! and really neat. I sit in my recliner that's near my tank and watch him dart in and out of the rocks.
Like Melosu stated "make sure they're eating at the LFS". You need to make sure ALL the fish you get are eating. Also, you'll need to add them 1 at a time, over several weeks. By doing it this way you let your tank slowly get used to the biological load and you won't get any spikes or nuisance algae blooms, ideally.