Chiragp,
Unfortunately all of those upgrades will cost major $$$. Engine wise...I think Benzmac still has a C36 engine. Forget about the M119 V8's. They had enough trouble fitting (and cooling) in the W124 engine bay.

An M104 E320 engine with twin-turbos could also be good. Provided you found a good E320 engine. OEM compression power levels are in the 300HP range. If you are going to mess with lower compression go with the C36 powerplant.

As far as brakes go...I'd try either 400E brakes or 500E/500SL binders. The 400E kit will fit under 15" wheels, the 500E/SL kit needs 16"ers. There is a Brembo kit for about $1,400 bucks as well. Of course, there are always bigger dollar brake upgrades but those are your best bang-buck options I know of.

Your tranny options are limited. You would probably have to get a custom/modified 5-speed with modified/custom clutch or pop in the 722.3 automatic from the high-torque cars.

Bodywork and whatnot is personal taste. Given the desire for bigger tires and stuff you might be better served to start with a 190 16v.

I know of a guy who put a C36 motor in a 16v with LOTS of custom work +other mods. It is supposed to be good for 4.8 0-60 runs with a manual. Before you go doing major surgery you may want to give him an email. If you are still serious I can get you an email addy. The project will likely cost much more than you originally figured. There are tons of little things that can creep up on you when doing something like this. I wish you the best of luck in your endeavor. Please let us know how it goes!

Hope this helps...Lee