Regarding the Gentex, you could just phone FlightSuits in the US and ask them what the current export situation is. They did make and ship my custom-fit HGU55, but that was a few years ago now (and there was export hassle even back then).
I'd forgotten about the Peltor helmet solution suggested in the thread that motivated me to get out the kitchen scales:
http://www.pprune.org/private-flying...erobatics.html
Certainly worth giving Peltor a ring.