There doesn't seem to be too much interest in the 200k models on here, but I know there are a few companies that offer upgrade kits. I just got my CLK200K back from my wife who has been driving it the last year and a half, and now i'm looking to do some upgrades too.
I know Carlsson, Brabus and Kleeman have pulley kits for the 200K engine, and they all have exhausts as well.
I haven't decided which one I'm going to go with yet.
2007 R350 SWB
2005 CLK200 Kompressor
1989 MR2 Turbo
Gone but not forgotten:
1995 Skyline R33 GT-R V-Spec
1998 SLK230 Kompressor
2003 C180 Kompressor Sports Coupe