An EMS is the closest thing we have to an outfitter here on Long Island. The people in this store are friendly and usually helpful. There's a limited selection of gear and a large selection of clothing. But, you can get everything you'd need for backpacking, if not the particular make and model you're looking for. Although they will order anything you want made by the major manufactures.
All that being said, REI is supposed to open a store in the same area this coming fall.