Burky,
You car is a 993, right? It's not really addressed in this specific forum as after the 89 cars there are separate forums for the 964/993/etc.
I would suggest first checking out Elephant Racing and plow through their offer as they have lots of videos that address a good deal of Porsche suspension repairs and upgrades.
They offer plenty of stock replacement parts as well as fancy racing type stuff.
Elephant Racing
Then look in the 993 forum here and also consider Rennlist.com.
I used them to replace some bushings on my 81.