Ya, crocodile gar (alligator gar cross) is out due to size and difficulty to obtain, as are alligator gar most likely. I'm sticking with the longnose gar, but the idea of adding some giant catfish sounds feasible as long as the two species can coexist. As far as feeder fish go, I stock the pond with minnows plus the bass spawn yearly providing larger food options for other fish.