My brother and I are in the process of doing our research regarding the building of a pond in New York state. We are in a very Northern type climate, so we decided to go with smallmouth bass. Like you, we were originally largemouth guys, but a friend took us smallmouth fishing up in Maine one fall and we fell in love with them. It was a great experience and the thought of having a pond full of bronze footballs to catch is very enticing.
The nice thing about having a smallmouth pond is that you don't need to have bluegills in your pond. A species like the Pumpkinseed Sunfish might be a much better option. They will help to control snails, and mosquitoes in your pond, and they aren't the reproductive machine that the bluegill is. Their size stays much more within the realm of viable smallmouth forage, which is another benefit.
Bluntnose Minnows, Golden Shiners, Killies, Crayfish, Grass Shrimp, and maybe some other kind of minnow or shiner that I am not familiar with are really all that you would need besides your smallies.
This leaves a greater percentage of the biomass of the pond to support to the growth of your main predatory fish.
These are just things to consider. I am not trying to tell you what to do with your pond. These are just things that we considered when making the decision about our own pond.
Good luck with everything.
