I’m very happy with the Marmot Helium Long I just received from MammothGear.com steals and deals: http://www.mammothgear.com/odeals.html
It was significantly less than anyone else, their service was great and they were fast and friendly. They now have the womens helium (and a few other nice bags) for $100+ off.
(No relationship or interest in the company).
MikeB
