To me, black or silver on a Merc is a bit too typical, so I say go for gun-metal grey like the those in the offical photo, or a pearl white one. The 3rd option, stick with the E63 is interesting. Do you need the extra space in the E63? If not then go for the C63, it will be a more rewarding drive.

I assume in the U.S, the C-class isn't as well respected as the E and the S is that true? I don't think you will care about what the un-educated will say about you crusising around only in a C63.

How about a CLK 63 Blackseries? It might not have the newest shape, but what a beasty looking machine. It handles well and it is prety much ready for any track action. It might not be so comfortable as a daily drivers car, but you have your ML63 to do that right?