I find a pretty decent selection at the grocery store. I've had no problem finding chicken and beef livers and hearts (not considered an organ) as well as chicken gizzards. When I run out of selections I intend to buy some online, either in whole animal grounds or individual whole organs. If you want chicken backs, you can just buy a whole chicken at the grocery store. I have no idea what the processing plant would have or if you can buy from them directly. I'd just give them a call.