Ponds :
You are right that it would be fun to catch a few. I think you can do what you planned if you have and maintain a good forage base. There are a number of ways to do that but it will take some effort. But that is what makes it fun to try. BG and tilapia combined is a good way in my opinion. I bet the cats will feast on the tilapia when it gets cold. I don't know about the numbers for your pond as that will be a function of carrying capacity and water quality. I will try to locate a seller. I will post if I find one and good luck with your pond.
Try this link/source - you can email or call.
http://www.sepond.com/CHC.html