Check out
http://www.190revolution.net for info on those cars. They're pretty nice, and handle well. I am 99% sure that they were all N/A cars, Mercedes eventually made a couple of evolution of the car for homologation purposes; unfortunately we never officially saw the final evolution of it hear in the states.
Considering you're dealing with a car that is over 15 years old I would do general maintmance and make sure everything is in perfect working order before I started to modify anything. Go through and replace all the suspension/anti roll bar bushings, chances are they're pretty worn; this would be a good time to upgrade them to polyurethane bushings, something you'll probably end up doing at some point if you plan on tracking the car. Also check all the motor and transmission mounts, ball joints, ect. Check the brake lines; maybe replace them with braided stainless steal lines, and a higher performance fluid. The calipers could probably stand to be rebuilt as well, so you might as well replace the pads with something a little more high performance. Flush and replace all fluids (oil, gearbox, diff, coolant, ect), perform a check up and do general maintmance on the engine. I could go on and on but you get the idea. While this may not sound as exciting as 18 inch wheels and twin turbos it will certainly make the car a lot more enjoyable to drive, especially in the long run. Plus you should learn how your car handles in its stock form before you starting doing any real modifications. Get a few auto-x’s under belt and then sign up for a track day or two.
Also since your possibly buying a homologation car learn its history and what the car was built for before you start "modifying" it and potentially bastardizing a piece of history.
190 E
http://akamaipix.crutchfield.com/ca/...0712/benz1.jpg
Evo 1
http://www.k-t-b.de/bilder/zeus/03.jpg
Evo 2 - some may say rice, but even the gaint wing was designed in a wind tunnel for touring car/DTM racing.
http://www.classicdriver.de/upload/i...2732/img01.jpg
DTM car
http://www.pistenclub.de/amgmercedes190evo.jpg
http://www.zandbak.net/classic/92dtm/006.jpg
While the 190 E is a pretty nice car, and a somewhat successful race car, it was greatly over shadowed by the e30 M3.
http://www.benzworld.org/gallery/pic...04112153PM.jpg
http://bmw.isuisse.com/alleman/dtm89bmw.jpg