HELP! 10V Turbo I-5 piston sources needed!!!

[Ameer Antar]

Hey. I know I'm crasy... but what are all my options for buying a new set
of pistons for an MC OR KH turbo motor? I need to tell the shop what bore
size to go for, and the owner wants me to find out all the possibilities.
Are they even available through Audi? Are there any non-OE but non-custom
aftermarket companies that sell these? Any engine rebuilder's parts links?
The shop owner only works on American (his bore machine will just barely
fit into the KH holes), but he says there's companies that stock pistons
for every car, but they're not OE. He only has one foreign catalog. Thanks
yall.

-ameer