If your thinking of lowering just go for shorter springs and shocks all 'round.
Mine's on Eibach springs with AP shocks.
Try our site sponsor @DPM for choice and price.
I have just bought a A4 B6 Avant SE with 218k on the clock. It has a saggy back end and the rear is very low compared to the front. is it likely to be the rear shockers that are just tired? was thinking of replacing the front and rear shockers and maybe a 30mm lower as well.
All help appreciated
Do you have any pictures and lowering heights?
From what you've said and the mileage I'd say new springs and shocks all round ASAP.
Damian @ DPM Performance
Here's some recent one's, doesn't show the height very well in these photo's as I usually take them at a bit of a height:
May have more in other threads I've made or you could see what images Google pulls up under "eibach pro audi b6"
Might also be worth fitting an S4 or RS4 rear anti roll bar while you're in there.
It won't affect the ride height but will very much improve the rear agility of your Avant