The only significant suspension (performance that is) difference is swapping to E55 spec suspension pieces. The W210 does NOT have "sport" suspension as did the previous generation E-class (W124). I'm not sure if the spring rates would be perfect for your diesel engine but it would be the most sporting (100% OE) option out there. You could try talking to Luke at Tirerack for a suspension recommendations (Eibach/H&R springs with Koni/Bilstein/etc shocks) If you do E55 spec suspension then the next logical step would be E55 spec wheels/tires. Doing that however you would be wise to roll the fenders (as did AMG on the E55). It takes ALL of the elements of the suspension, tires, bodywork, etc working together to get best results.

Hope this helps...Lee