If you are catching crappie and everyone is happy catching them then I wouldnt bother adding another species, you have trout as well right. I put sunfish in my lake and they exploded like mad this summer, they spawned and were sitting on nests from june to august it was crazy...
here is a video of the sunfish, really fun to watch these little guys all over the place but Im going to have to get some LMB in there to start managing numbers.
