New Barrel
Howdy Satkong,
Go to Springfield Armory's website and search for 1911 parts. They list a one-piece, stainless "Drop-In Service Barrel" that'll run ya around 90 bucks delivered.
I've had good luck with those barrels, and even used two of'em in a twin Essex
Commander Clone project with my ex-wife's oldest man-child a couple years back.
They only come in 5-inch length...so if you need one for a Commander, you'll need to modify'em to work. The links were installed, and correctly fitted. They lock up nicely in the vertical plane, and the muzzle end is slightly oversized to allow better fit at the muzzle. They'll drop in with minimal fitting in most Colt, Springfield, and Essex slides...even USGI slides. Very good barrels for the money and time involved.
Keep one thing in mind, though...While the barrel that you get will very likely drop right in and work...it's best not to count on it. If you try one, and run into a problem, just sing out.