Welcome to the forum, pondenvy.
Where in Iowa are you? Can you describe your lake a bit more such as how old it is, how deep it is, is it currently stocked or not, etc. Do you plan to feed your fish or not?
Then can you describe your goals a bit more. Do you plan to fish this lake heavily or not? Although it is seldom mentioned in this forum, in my opion, this is one of the most important questions in dealing with our lakes. Do you want to grow fish quickly to eat or do you want to have high catch rates? Then, can you tell us why you want each species? What do you think each species will add to your fishing pleasure?
Next, buy the book "Iowa Fish and Fishing" from the IDNR. It is outstanding!
You're right, LMB and BG will be the basis of your fishery. I think that almost everyone here would suggest channel catfish rather than bullheads. Bullheads can be very hard to control. Redear sunfish have a good chance of surviving anywhere in Iowa but expecially in the southern half. They would add a great deal to your lake.
We have both walleye and yellow perch in our 4-acre lake that was started in 2000. The yellow perch have been essentially eliminate by predation by bass and catfish. That long slender shape goes down too easily. The walleye have a hard time competing for prey until they get to about 14". That means that all of my walleye restocking must be fish 14" or longer. It's worth it to me but it might not be to you. However, when stocking all little fish, it is no problem.
As to crappie, we have both black and white crappie although most people would suggest you use only black crappie. We have such heavy predation in our lake that we have NO crappie reproduction. The Missouri DNR has some excellent articles about raising crappie in small lakes. The secret is to have heavy predation but to allow some reproduction.
One idea that you will see here more is that of stocking, growing and harvesting fish. You will read about it most with Hybrid Striped Bass. Non-reproducing species are much, much easier to manage than are reproducing species. This opens so many more opportunities.
I hope some of these ideas help in your thinking.
