I bought them from that ebay seller, and they look gorgeous, they changed the total appearance of the car's interior. My SLK has them so it was a no brainer.
The installation is easy but a little tricky. The accelerator one is absolutely easy, just slip it in place and it's done. For the brake you will need a little more of patience but by no means it's hard to accomplish, after some tries, a couple of pinched fingers and you will be done. They consist in a rubber cover with the aluminum plate attached to it, so just remove the original rubber cover and fit the new one. My tip is to start from right (closer to the accelerator) to left.