damn Del, you seem to really love your fish.
Is the main reason the overstocked tank or your dad? What kind of pressure is he putting on you?
That would be a shame, but make sure they go to a good home.
PS - rottbo - I think your idea is a very good and honourable one, HOWEVER. I honestly think you are fat too hasty. Wait until the pond is setup before adopting more big fish. Even with your best intentions, stuff happens. Like you've already said, the 7500 has been shot down.
Just like the old adage of buying the biggest tank you can, then buy the big fish. Not buy a baby monster in a 10 gal, and plan to get a 500 6 months down the line.