Re: A2 buffer tube,spring and buffer
Like all things AR right now...get yourself to MidwayUSA, Rainier Arms, Bravo Co, etc., etc., etc., and get on the "Notify" lists for when the kits come back in stock.
Alternatively, post a WTB thread here as well as keeping a watchful eye on the BARFCOM EE forums.
Aside from that...I don't know of anyone with any stock kits in stock right now.