You can use Bilstein HD(Non Lowered/Stock Spring set up), Bilstein Sport(better coupled with Lowering Springs), Koni Red, Koni Yellow(Fully Adjustable).....I personally used Koni Yellows set at Mid Firm/Soft(Middle setting) and is very pleased with my suspension mod.....If you are not changing your springs and will still use your OEM Springs, I highly recommend the Bilstein HDs-they are the same shocks an E55 uses......BTW, ALL W210 97-02 Shocks are interchangable and WILL FIT ALL E320/430/55 EXCEPT those equipt with the Air Suspension.