yeah im 17 too, i went into the hempest on saturday for my friend to get a mini bubbler.. i think they only have one hookah that seemed pretty small but they got some nice bongs there.. just really overpriced
another dope place is buried treasure which is right down the street from the hempest (on newburry st), its pretty ghetto but i know they have probably the best selection for bongs, not sure about hookahs.
other than those two theres also kangs and sugar daddys, ive never been in either because they ID at the door and im really not sure if they have hookahs.