Dealership VIN gives them the best info on the chassis, model and build date, which might make a difference if MB had a mid-year production change (usually electronics, brakes, etc.).
Bilsteins and Koni are the aftermarket shocks of choice. MB Sportline and some AMG shocks are Bils. The Comforts are the OEM replacement, the HD is designed for heavy loads, trailering and the Sports are for lowered cars.