Each valve body is a custom job. Although the modifications are basically the same you need to provide the year and serial number off your valve body toa competent trans specialist so they can determine what is appropriate. Unfortunately, this is not one of those off the shelf easy upgrades. You will need to do some digging on your own unless you happen to live near Mario Aristides in Miami Florida. He runs Independent Transmission and is the smart guy on Mercedes. He may be able to help you with your questions.
As far as the shift kit I am very happy with it. BTW, Mario designed that kit and Superior sells it. I installed it myself but if you don't have any experience with a valve body you might want to let a shop do it for you.