Howdy MFFL, and welcome aboard.
How deep is the pond now when it's full? If it goes dry every couple of years' then you're right... correcting that issue will obviously be your highest priority.
An acre is big enough to provide a good "eatin" pond, but if there's gonna be major dirt work to correct the leak, you may have the option of going bigger and deeper for not much more money. Definitely would be the time to do it all. I would think that a typical Bass and Bluegill pond would be what you would want, and there's a surprising amount of variance in species between those two fish. I'll stop there and let the more informed folks take over.. you're in good hands, just hang tight! Someone will be along directly..

"Forget pounds and ounces, I'm figuring displacement!"

If we accept that: MBG(+)FGSF(=)HBG(F1)
And we surmise that: BG(>)HBG(F1) while GSF(<)HBG(F1)
Would it hold true that: HBG(F1)(+)AM500(x)q.d.(=)1.5lbGRWT?
PB answer: It depends.