The wild caught fish issue is a difficult one, while i do have some semi rare catfish that must have been caught from the wild it does upset me to think that they were once swimming in a huge expanse of water and now they are confined to the 5 and 1/2 feet of my tank.
One very depressing tale of wild caught fish is when one of my lfs imported 3x12"+ wild caught frontosas, this was over 6 months ago and 2 of them are still there in their tiny 18" tanks, the reason ? They are priced at £160 each while in the next tank they have 3" tank bred frontosas for £6. Whos going to pay £154 more for what as far as anyone is concerned is the same fish ? Any serious breeder will get their stock direct from the importers for less money.
As for trying to recreate the natural enviroment of the fish exactly, its impossible in almost all cases. Most rift valley cichlids come from deapths of 30 - 40 meters down, not many tanks that size around i think, and even the longest tank could never recreate the natural flow of the amazon or congo rivers. If your into recreating exact biotopes youd better stick to killie fish, bettas and other fish which live in tiny puddles, other than that all you can do is try to make the fish feel as comfortable as possible and keep the water conditions perfect.