The stock bell-hiller head for the HB CP2 is supposed to fit the BCP fine. It's made of plastic, so it's only about $20. Every site I've found that sells it is out of stock right now (except one in hong Kong that wanted $23 shipping). Heli-hobby has the best price so that's the one I've been watching. Bdavison said the BCP becomes an entirely different machine with bell-hiller.

This is the first I've heard of "head dampening shims" and I've still got the 2bb grips, just switched the washers and it seems to be fine for me.

By the way, heli-direct got a new shipment of their 1300 mah 3s lipos in for $19.99. 7C so they should be fine for the blade. I'll find out, orders on the way.