building a lower for stag upper, 16 '' barrel. as far as the stock goes for the lower. i know it has to be carbine buffer and spring for the gas system. and i know NY the stock must be pinned. is it possible to order a stock and have it shipped? do i have to go to the LGS or gun show? i was hoping to get the magpul MOE. is it possible to run a carbine buffer n spring in a fullsize stock if the need arises?