First, get a big chiller. Then, get a bigger chiller.
If you want to keep an edible species, look to the blue crab. They can be kept at room temp. Unfortunately, like all large crabs, they're major predators and WILL eat any and all tankmates (including their own species).
I don't know, If I had a big enough tank to keep some Caribbean Spiny Lobsters, I don't think i would have a problem eating them, and even if I did as soon as the steaks were on the grill and the drawn garlic butter on the table, they would be on their way to the pot. ;-)