Black Mercedes: Maybe the key issue is the width and offset, I thought that I read in the C36 lit that 17" wheels were required to clear the front calipers, but I could of been mistaken.
DTM FAN: I can not really comment about the E420 front brake setup. I am sure they are superior to the brakes on the C220, but by how much I do not know. It would be a much easier upgrade if you could locate someone who has done such a swap, that way they could let you know what problems to expect. Since AMG did the swap on the C36 for the SL600 front brakes, you should not have to fabricate anything, since all parts are readily available from your local MB dealership. Now doing the e420 brake setup on the C220, might be a different story
I have some pictures of my C36 and the brake upgrades I did to it. The url is