Need source for new turbo or rebuild

[Robert Rossato]

I have a friend with an '02 A4, 1.8T, that has a potentially blown turbo
and asked me for recommendations for a source for a replacement turbo.

What are the recommended sources for a replacement turbo other than the
dealer.  I'm assuming the original is a KKK K03, right?

Also, recommendations for qualified turbo rebuilders would be
appreciated.

Thanks,
Bob