I thought the largest LMB in the pond were 11 inches.

Rex my suggestion was tilapia at least 5 inches (based on max 11 inch LMB) and use 10 to 15 lbs no matter if they were 5 or 8 inches. Difference in numbers per size offset by anticipated predation on smaller fish.

I am not sure he can find 8 inch tilapia in TX in May when temps are good (may be earlier near his location). My guess is he will do well to find 5 inch fish. Start calling now looking for them.