The 130bhp TDi A6 is the one to go for if you're hell-bent on the rings on the grille but the Passat (with the same engine) will be more comfortable and responsive to drive.
If you are interested in a 1.9TDi 130BHP Audi A6 I am selling one with the following spec. PM me if you are interested:
2003 1.9 TDi Sport 130 BHP
87K Miles, Full Service History, 1 Owner
Silver, Full Black Leather, 6 Speed Tiptronic Gearbox (with Sport option)
17" Alloys, Nokia Hands Free Kit,
MINT Condition.