The CLK55 comes with Bilstein HD....
I have a set with only 3000 miles on them. They are actually a little softer than the sport shocks. If you try to buy the OEM Bilstein HD's you will end up paying about $1000 If you need replacements, I have a set of 4 OEM Bilstein HD's that were used for 3 months. I'll sell them for $100 + shipping if you want them.