You don't have to want to go lower to want better dampening qualities. Besides, you are likely to pay more for OEM from Audi than for good aftermarket. ECS Tuning carries stock fronts for nearly $200 each! Probably looking at $800-1000 all the way around from a dealer.
If you have the money maybe a set of Koni FSDs? Probably handle and ride better.
Unless there was a problem in manufacturing, like bad tempering, your springs should last damn near forever. Koni Yellow set to full soft would probably work just fine, even if they are more "sport" oriented than the FSD. At that mileage, new shocks/struts, and a suspension "refresh" kit (bearings, bushings, tie rods, etc.) would probably make it drive like a new car.