I recommend that you don't keep those fish in a tank. They can get very large. There are also way too many fish taken from the wild for the aquarium trade. I am writing an article right now about it for Aquarium Hobbyist.
I'm not trying to ruin your ideas, but I think you should just stick to the fish at the pet store.
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Phishie

"An ounce of prevention is worth a pound of cure."