Beardy,
Your best bet is to find a stream near you where there is a native population of northern redbelly dace. I have found many different species of minnows locally including mountain redbelly dace, rosyside dace and after more than a year Satinfin shiners. The minnows are difficult to buy unless they are fatheads, golden shiners, etc … I can only speak from my experience with a flow through pond. It has had excellent reproduction from the daces. I had the best results trapping them using the silver minnow traps using dog food to catch them in local creeks. I hope this information helps but you really should find out if they reproduce in a pond without constant water flow if that is the case.