Buna-N is the O-ring material I use.
I installed chrome plated brass fittings made by 'Colder'. The Colder part numbers are; LCD17005
(female) and LCD22005
(male). Those links will take you to the QuickCouplings.com website. Another seller is Omega.com (Omega item numbers FT-LC220-05 and FT-LC170-05)
, but they are a bit more expensive. part numbers
Unfortunately, I bought mine from www.mscdirect.com
(item numbers #88080445 (2 each) and #88080486 (2 each), but I really wish I would have known about QuickCouplings.com, where the fittings are significantly cheaper.
Anyway, the Colder brand fittings are really nice fittings. Both sides have positive shut-offs when disconnected. For what it's worth, I re-used the OEM stainless steel crimp-style hose clamps when I installed my QD's. I've had my fuel tank off several times after installing the new QD's...and I must say, I'm really pleased witht them. In fact, just had my tank off yesterday. Put a couple of new O-rings in and back together in a snap.
I also bought 100 replacement O-rings (for a whopping $1.87). I bought the o-rings from http://www.mcmaster.com/
, part number #9452K19. Industry standard, size - 011, Buna-N, Hardness-Shore: A70.