Springs and sway bar are different. Nivomat suspensions use weak springs and a heavy sway bar along with the special shock.

IPD may have a spring kit and with a 92 you have some choices on shocks and I like Bilstein touring- but I only have them as a strut cartridge on the front as I have the Nivomats on the rear of my '93 965. The Boge shocks on my V90 are a little too soft for my taste, but the cars have completely different suspensions. If you want a boulevard ride, perhaps Boge is the best choice. Bilstien Touring is a little firmer but not bone-jarring like Koni or Bilstein Sport.

Changing to conventional shocks without changing the suspension is dangerous. The car will bottom out without changing the springs and will have oversteer if you change the springs and the shocks (means the rear end will break loose). Oversteer can be compensated for but family cars generally are set up with a bit of understeer because it is considered safer for a novice driver in an emergency. Nivos are great shocks. I loaded my wagon with 30 boxes of tile and it leveled right out. It's a beautiful thing. If you have the $$, replace them.

Bob