You might want to check this out for some info on how to do what you want:

http://mbclub.co.uk/forums/showthread.php?t=11872&highlight=spring+pads

I often hear that 90% of the users on this board can't be wrong using Bilstein. MB, Ferarri, Audi, Brabus, AC Schnitzer, and the entire Formula 1 circuit seem to have gotten it wrong and decided to use Sachs.

Then there's the argument that Bilstein has a lifetime warranty. Sachs does too. They'll even replace an OEM shock if it has their name on it, which Bilstein won't do.

I've used both Sachs and Bilsteins and can't really say I was able to tell much difference in performance. What I can say is that I put 172,000 miles on the last set and I saved a lot of money when I bought new Sachs.

Here's a link to the Sachs Web Catalog if you decide to go that way:

http://webcat.zf-trading.com/index.asp?SPR=4