I have never kept just CC and CP in the same pond, but I don't see them being impossible to keep together. CC are rather cheap to buy at larger sizes. So even if they don't spawn, buying and stocking 8"-10" fish wouldn't be overly expensive nor difficult to source. CP will spawn over aquatic vegetation. I would stock FHM and GSH and then the CC and a year later the CP. 20 or so adult CP per acre should get you started...