Unless you are in an area that rarely, if ever freezes, I would stock Northern Bluegill. Coppernose BG (CNBG) will either die, or grow poorly in waters that get any annual icing over.
HyBCP have no known instances I'm aware of where there was any overpopulating in ponds with LMB present. HyBCP are treated like channel catfish, a put and take fish, meaning you will put in new fish as wanted when some are removed.
What are your fishing goals? Larger BG? Larger LMB? A decent size mix and frequent catch rate?
