My personal opinion is that you can have any fish you want in your pond, on the condition that you know what to expect from each one and the community as a whole. Once you understand your goals these fine folks will gladly help you find the best combination of fish to meet them.

Understanding the biology and life history of fish is the second step to selecting fish for your pond.
Here is an example, yellow perch are early spawners who lay huge masses of eggs. But YP year classes compete and a strong yr class will suppress the number and growth of the next 3 or 4 yr classes. So if you put YP in your pond, and they reproduce well, you will have a cyclical population. Every 5 or 6 years you will have really good YP fishing, the rest of the time most of the fish will be too small. You will always have some keeper fish, but most of the time the dominate year class will be smaller fish.

If the right managment techniques, proper care and money, and a sane stocking program are instituted from the beggining you can have great fishing.

One thing I consiedered with my family's pond is "what can I not get from other local lakes?" Do you want to catch 24" walleye every time you go fishing? or is thier already a lake you can do that on? Is it easier to find 8" BG or 4lb bass near your house?
The reason I point this out is that it ussaly isn't hard to find bullheads, but if you really want them...