Derek,
You are discovering what I have known for quite awhile. It is a whole lot easier to plan & develop a stocking plan than it is to find the fish especially if your plans are for stocking something other than the normal LMB, BG, HBG. I have driven 3.5hrs one way to get a few SMB and YP. The difficulty of locating and obtaining some species makes your fishery that much more unique and valuable.
Imlay City fish farm is probably your best choice. Ridgeview Fin Farm Ridgeville Corners OH (finfarm.com) is about 1 hr south of Adrian and MI line. Laggis is worth the drive and has very good quality fish and several species are pellet trained.
Golden shiners are hard to locate in MI and OH. Shiners are not as hardy and not as popular as FHM thus only very few hatcheries carry them. If you want g.shiners you may have to go back to Jones. Maybe meet the truck (cell phone tag) when they are on a northern OH or southern MI delivery. If you want a really hard fish to locate stock some bluntnose minnows which do very well with y.perch and SMB if the pond has some underwater weeds for cover. My initial stock came from local waters.
Best way to check on the status of your fish is as suggested - fish with some live bait, worms or minnows from your pond. It should only take catching 4-6 fish to get an idea of what growth has been like this summer.
