The extremely astute Nancy Friedman suggests looking into stockist, noting “US companies are appropriating this BrE term… Until recently, the more-common term would have been ‘where to buy’ or ‘retailers.’” Never even once having come across this term, I would have doubted her, had she not supplied four web sites that list the stockists from which one can purchase their stuff:
Nancy notes that Remedy Quarterly, a magazine, is based in Brooklyn.
I am now convinced that stockist is indeed happening in the U.S. However, it has not yet appeared in the mainstream media, only, apparently, in commercial communication. This puts it in the same category as bespoke: a phony, hype-y word that exists–and one hopes will stay–in the realm of advertising and promotion.