These are excellent suggestions. Rather than catch wild, I'll shop around for local hatchery. I think there are some in Mass. NH requires permit for fish import, but I've talked to the state folks and it is not a big deal to get for a closed pond. $10.
So male Blue Gill (or HBG if available) and female Yellow Perch. Maybe next year I'll have to come up with names like Blerch or Yue Pill? I wonder if that has ever happened - not in the wild but in your hey-lets-see-what-happens sort of way. I suspect you PBer guys have thought about it. Cool...
Big thanks to you, Bruce, Theo, Cecil, Bill. Even with the supplier, I like the idea of double-checking the sex sort. I'll post the pics.