For sale I have a genuine Bosch DV 710N. These are the standard on the TT and S3 225 and are a great upgrade for 1.8T AGU's with a remap as they're capable of holding more boost.
Also I have the N75F valve which is the revised boost control solenoid valve. Discount for forum members.

710N link:
VW Audi Golf GTI A3 S3 TT 8L 8N Diverter valve 710N 06A145710P | Engine, Engine Parts & Transmission | Gumtree Australia Inner Sydney - Waterloo | 1131643227

N75F link
VW Audi Golf GTI A3 TT 8L 8N N75 turbo boost solenoid valve | Engine, Engine Parts & Transmission | Gumtree Australia Inner Sydney - Waterloo | 1131643299