1) cut the braking surface off your rotors and convert them into hubs.
2) open the center register of 2005 Mercedes S500 brake rotors to fit the truck center registers. Redrill the bolt pattern to match.
3) make a bracket to mount the proper caliper in the best position.
4) if using a multi piston caliper be sure the wheels have the spokes far enough away from the mounting surface to clear big fat calipers.

Another option is to send me the truck spindles and enough cash to build the setup you want.