^ Any shop that has a NRG account can get you one. Will they is an entirely different question.
USWE packs have the huge advantage of set it and forget it harness straps. I run mine as tight as they'll go and just unbuckle for the uphill if I'm feeling restricted. Even unbuckled it moves around less than any other pack.
I had the privilege of seeing NRG's stock on USWE packs and let me tell you its pitiful. Just buy from CRC or direct. Sucks for shops but if their suppliers aren't stocking product then everyones hands are tied.
Sidenote: NRGs Chromag inventory was pitiful when I last checked as well so if a shop can't get you a chromag item I'd take it at face value.