Ed, so far my Googling has not located a source for the helmet you describe (not even the DC website itself). Could you kindly point me to your supplier? Thanks.
Edit: found it, along with lots of other aerobatic goodies. Oh joy, a 9G kneeboard!
http://www.aerobaticproshop.com/davi...helmet_kit.htm
I must say that $386 seems a lot for a plastic helmet (compare the prices of skiing and climbing helmets).