Hmmm, not too keen on the Marine Betta although I am making that judgement solely on pictures from the internet. Thanks for the recommendation though. I'd really like the grouper.
The LFS selling it also has a 2500 gallon display tank with a black tipped shark in it and little else. I'll ask if they would be prepared to take it off my hands once he became too large. They did used to have a large one in a display with an unwanted puffer and engineer goby. I don't think that tank was much bigger than mine though.
As for eating him (I read they are related to the Sea Bass), I never could. I'd be like Homer Simpson's eating his beloved lobster "Pinchy". *laughingc