I had Koni FSD's on my B7 A4. They were nice on the street paired with the stock springs.
While you're in there, replace the upper control arms, they have to come out for the front shocks anyways. All of the suspension hardware on those cars is single use, too. Replace it.
Now, what you dont want to hear, is the 'pinch bolt' on the knuckle holding those upper control arm balljoints in, is likely seized looking at the condition of the undercarriage that you posted a photo of. Just be prepared to deal with that by removing the knuckles from the car. There's no easy way around getting the pinch bolts removed, other than taking the knuckle to a machine shop. I've watched some youtube videos of this.... usually involves heat and air hammers. My bolts were seized, and I had a shop handle the shock install.
While you're in there, replace the upper control arms, they have to come out for the front shocks anyways. All of the suspension hardware on those cars is single use, too. Replace it.
Now, what you dont want to hear, is the 'pinch bolt' on the knuckle holding those upper control arm balljoints in, is likely seized looking at the condition of the undercarriage that you posted a photo of. Just be prepared to deal with that by removing the knuckles from the car. There's no easy way around getting the pinch bolts removed, other than taking the knuckle to a machine shop. I've watched some youtube videos of this.... usually involves heat and air hammers. My bolts were seized, and I had a shop handle the shock install.