Here ya go! The prices may be out of date, but the part numbers should still be good.
WELDLESS CONVERSION (FOR KEG)
Get parts from wwww.mcmaster.com
McMaster Part No. Description Cost
4464K214 Stainless full coupling, 1/2" pipe size, $3.42
4830K171 Stainless Steel 1/2" Close Nipple, Fully Threaded, $1.69
98126A797 Stainless Steel Shim(sold only as a pack of 10 @ $10.38) $1.04
9396K32 Silicone O-Ring (sold only as a pack of 50 @ $14.53) $0.29 (x2)
4429K124 1/2" Locknut, Brass (with groove for o-ring) $1.30
4190K22 1/2" Brass Ball Valve, Full Port $6.