Here's some sources for llama parts:
http://www.e-gunparts.com/model.asp?idDept=149
http://www.jackfirstgun.com/ (Pros shop here first).
NOTE: Revolver barrels are NOT something you can "do at home".
Changing the barrel REQUIRES a fair amount of expensive tooling and the knowledge of exactly what to do, and how.
Attempting to do it with "expedient" tooling is how you ruin a gun.
As example, the old gag of using a hammer handle to twist the frame off is pretty well guaranteed to destroy the frame.
Barrel removal requires a special frame wrench with plastic inserts that are made to fit ONE specific brand and size frame.
To fit a barrel requires:
A lathe to turn the barrel shoulder so the front sight lines up.
The special frame wrench with inserts.
Brass, aluminum, or hard plastic barrel clamps.
A barrel vise.
A special cutting tool that works down the bore to cut the rear of the barrel to adjust barrel/cylinder gap.
A special cutting tool that works down the bore to re-cut the forcing cone.
A special plug gage to gage the forcing cone.
Here's a hint. Trying to do it with a file and some wood barrel blocks will destroy the gun.
Second hint: NO local gunsmith is going to have the right frame wrench inserts or barrel blocks.
In all likelihood, he'll try to do it with expedient tooling too, and botch it.
Sorry, revolver parts are hand fitted at the factory, and there are few to NO "drop-in" parts, and especially NOT barrels.
Best advice: Try to find the importer and find out who did their warranty repair work.