I would definitely NOT advise you to be licking fish from PetSmart, as their tanks are not the cleanest IMHO.
Seriously though, wonders killies get too big to be i a tank that size. they will terrorize the other fish, demanding to be top dog. but man they sure are good looking fish. I have 2 of them, and had to separate them as they fought violently. My alpha actually chased another one out of the tank entirely. *Covered up that little hole so it won't happen again* These fish can (are) very territorial. They need room. He has even chased the dwarf gouramis away from the surface.
This guy might find himself in an ice-cube tray someday.