Rowly - Currently you seem to be on a pretty good path to a decent fishery. Adding or introducing some DIFFERENT species of forage minnows/shiners would be okay in the spring. Thinning and predation from your existing bass and perch will limit the numbers in spring. New species of minnows/shiners may inhabit a niche/portion of the pond that is not being used by the existing species. See Pottsy, he may be able to advise or supply you with a different prey species since he raises some in separate ponds.. Competition will determine who the winners are based on the specific features of your pond.
I was just getting a little concerned when you started talking about next spring stocking excessive numbers of walleyes or the addition of numerous "adult type" LMB from the ONT Bass Fed. into your new well established pond. I would allow the existing fish some MORE time to grow and reproduce at least another season. Reexamine the conditions, the overall growth, and which species are doing best. Make a few minor adjustments if necessary. After a year or two, and then if you want or need some additional predators, add a few at a time and see how your pond system responds.
Always be cautious about adding lots of predators at one time. They can clean out and quickly damage a well established system in short order. Use a little patience grasshopper!
Don't jeopardise all the good work you've accomplished so far by getting in a hurry for lots of big fish. You will be surprised how fast the existing SMB & LMB will grow next year with an excessive amount of forage. That growth will be a lot less if you introduce too many more predators next spring. It's the rare pond that has too much forage. If you can get some pellet trained walleye next fall, I think you could safely add 80-120 in 16 acres. Give them a couple years and see how they "do" and compete and grow with the bass; they will be a bonus fish. Rowly, How big are your bass now? This will determine how big the added walleye will have to be.
