Barramundi are in the same family as the Nile Perch we have imported. I have never seen Barramundi available as they are more popularly a food fish. A friend of mine breeds them in the Pacific for this reason. Good luck with your search.
They are probably at least 12" last time I was there. I'm sure if you are chinese and chat with the guy he will probably sell you a live one. Only reason I say chinese is that most of them don't speak 2 words of english.
Shoot. I'm not chinese,lol. But guess 12" is to big anyways. I wish I could have them that big but it would destroy my other fish. I want one around 6-8" so it's around the same size as the rest of my fish. If my fish were bigger I would get a bigger one. I really think these fish look their prime at 18"+.