The Bilstein shocks are gas charged so they will want to remain fully extended. If you raise your coach up to where the front wheels are close to coming off of the ground you will find the point where the new shocks will just slip right on to the existing mounting points with minimal hassle. Be sure that you have jack stands under the frame before you do any work under the coach.
If you look under the front end of your W22 frame you will see that there is already two rubber bumpers(may be gray or white) that are almost exactly like the Sumo Springs. I do not think that the Sumo Springs would help by replacing the rubber bumpers that were installed at the factory.
