The Civilian Marksmanship Program sells receivers, complete rifles, and accessories upon completion of their purchase requirements (which are not difficult to meet). You'll start off buying a receiver, but will wind up with a full safe in no time, so be careful. :)
Dude, been there! TWO larger safes and four fireproof file safes for the small stuff. I know about the CMP, but I would prefer not to get my stuff from such a public concern. I've been trolling through the gunshows looking for the worst beater with a good receiver, frankly. I have everything I need to bring one back to life :)