I'm new to the AR arena and I'm shopping around. Palmetto has a 14.7" barreled upper assembly that is unpinned. Could I have it shipped to an FFL gunsmith to pin it before I take possession? If this is an option, who would you recommend I contact? Is this going to cost more than it is worth? Maybe I just sit tight and wait until something else comes along? Any advice on the matter would be welcomed. Thank You.