Not to be a stick in the mud, but the Cp concept is a little outmoded. While what you are saying is true (the Cp moves), mathematically, it is much easier to evaluate a wing with a Cm (a moment arm acting around the Cg). That way, you don't have to do the calculation as though you are chasing Cp vs. Cg, you just have to know what the magnitude of Cm is.

What you really want to say is that the idea wing section for a heavy model is one in which the pitching moment is reasonably small through the desired flight envelope, and has the right shape near the stall.

Matt