So slowly I've been taking control of my pond and I think I'm ready to stock!

In my 1/2 acre pond currently there are 2-3 large Koi, 6 grass carp, potentially some black catfish, and several hundred (if not thousands) of goldfish.

I'd like to be able to fish in the pond and know the goldfish need a predator.

I'm thinking of stocking LMB and BG and given the current population I'm not sure I'd need anything else this year.

So a couple of questions given this: 1) what should I consider stocking and in what quantity? 2) any recommendations on a fishery in the Ashland, VA area?

I had bad algae problems the first year, better second, and hoping for even better this year. I also have a fair amount of grass (hence the GC).

Thanks!