All the manufacturers will sell you a complete barrel, but if wait time is an issue then Shilen, McGowen, Lothar Walther, and maybe others build pre-fit barrels that are already finished and ready to be shipped.
Go over to Savageshooters.com and look in the vendore classifieds section, under "Northland Shooters Supply". Jim is one of the nicest guys to deal with, and wont hang up the phone till he is confident you are getting exactly what you're looking for. He sells McGowen and Shilen.
Northland Shooters Supply
BTW, Be sure to replace the factory recoil lug with a trued precision lug from either Northland or from SSS.