Okay, I found big bodied semi aggressive fish work the best (oscars and jack Dempseys are great). I never tried gars, my only concern would be that a test bite could be fatal due to small/thin body structure. The eel/pleco I would stay clear of as the are too immobile... if the fish is very seditary the more likely the fahaka will bite it again and again.
I had failures with small catfish, smaller snakehead species (rainbows etc) and anything too aggressive (the GT).... and now the pike cichlid I guess.
Growing out is fine but the puffer must be bought as small as possible and put into their home with lots of other fish. For some reason my lfs can get them quite easily at a round 0.5 of an inch... so they are proper babies. Then grow the up with all sorts of fish so they get used to seeing them as tank mates and not a meal. From there it's luck and trial and error!
My 220g at the moment is the fahaka, oscar, frontosa, ornate birchir and 2 large syno decorus.
Thanks Man, I know Gars have abnormally strong scales(a guy at my lfs said in college he struck one with a knife and not a scratch) so I think he can be alright(Thankfully he was the fish I wanted the most after the puffer)! I've seen other people house them with species of pleco, eels, and knife fish, but them I'm not as sure about them(especially the knife fish and eels due to their shapes and not really strong bodies). Maybe I'll experiment?
Anyway, for the grow out tank. Can housing them with rummynose tetras and less aggressive cichlids like firemouths work? The rummynose are cheap but might be too voracious of eaters and make the puffer grumpy, which is good for no one. The firemouths would be big enough to stand up to the puffer if he becomes too mean. I was thinking of establishing the grow out tank before the Puffer is introduced to make sure he doesn't become too territorial. For the fish I want to keep him with long term(Oscars, Gars, bichirs, etc), should I put them prior to getting him, or can I add them into the growout/150 later?
Feel free to add your input in on any of my ideas, like you a pufferfish predator community is the ultimate tank and I want to do it successfully.