I raise blugill in an aquaponic setup of my own design. They have proven to be exceptionally hardy, surviving for four days in a near freezing basement without electricity to power the system pump. Everything else died, but the bluegill didn't even seem to notice. Mine have survived water temperatures between under 40 and over 70 degrees.
They are omnivores, and I'm able to feed them organic pellet food from aquaponicsource and red wrigglers from my worm bin when they are lucky.
There are other sunfish relatives also native to North America who are quite flashy and attractive too, check out pumpkin seeds.
Carp are invasive and illegal to keep in an outside pond in some states, afaik.