I am looking to buy some threaded barrels to put silencer's on a few of my pistols. Other than Jarvis Barrels, what other companies out there make a quality threaded barrel? I am looking for the following barrels:

Sig Sauer P-220 Stainless (.578 x 28 Thread)
Glock 21 (.578 x 28 Thread)
Kimber Tactical Ultra II (.578 x 28 Thread)
Walther P99 (1/2" x 28 Thread)