Are you positive? Im not sure but isnt the 6 speed the same one used in the audi? They come stock 260? and with their chip pushes 300. Im not real sure about what i just said just putting in my 2 cents.
If you know all the specifications of the clutch (diameter, throw distance, etc), there's a good chance www.sachsracing.com would be able to match a unit. They don't have a part number for the MkV's yet, but I'm sure they will before too long.