Well seeing this is a 190E thread, I'll just post it here if no one minds
Personally, I think the best thing to do is use Front and Rear 95 E420 brakes. Slightly thicker, and you have more options for rotors IIRC. It is also more balanced.
All you need are new rotors, calipers and pads. SSBLs are recommended. You will have to trim your Brake Shields or remove them completely.
I usually use Potomac German for all my used car parts needs, but lately car-part.com is the best resource
I also used the 2-stage caliper paints after sand blasting them. With good pads like Axxis ultimates, and good zimmerman rotors (I stayed away from the Balos)
IIRC AMG C32 caliper also worked. I was even going to try ML500 calipers by Brembo. I actually have a set still in my garage. I Remember someone saying that the claipers actually bolt up perfect since MB never changed their mounting specs. If someone actually had the proper specs, I could confirm them. ML500 and ML55 shared the same calipers as used in the S55 prior to the larger 6 and 8 piston upgrades. These are also the same calipers in the S500. So I also thought the S500's X-drilled oem rotors would swap on well.
Also, since these fit under 16" wheels, I figured it was perfect for the 190E. Even though I had 17s, the 16 with 215/50/16s I had where great for almost all of my driving. The 17s just added the look for me.
I bleieve 2phast has taken the best journal of all the ideas out there @:
http://www.2phast.com/190E/default.htm
Enjoy