There was a guy on MFK that had them in a ~500G. If I remember correctly, he actually bred them.
Last time I saw them, Dave Hale at http://somethingfishyinc.net had some, but that was a long, long time ago. You might email him and see if he can even get them any more.
You might also call, Dave Schumacher at http://www.davesfish.com. If he doesn't have them, he might know where to find them.
I had one years ago that grew to almost twenty inches in the time that it was in my possession.
Jeff Rapps used to have them on his list pretty regularly and can probably get more.
That photo looks like a scene from the film in which the pair fended off a turtle as it tried to raid their nest.Seeing that video years ago was what made me want an Emperor Cichlid.
I had 2 that I grew out in a 75g from 2". Once they hit the 10-12" mark I sold them. They grow super fast and mine were not to aggressive. Beautiful fish but needs a monster tank or pond.