By "high performance" do you mean "high noise" = "more power?"
The exhaust in there is already pretty free-flowing. A popular mod is to delete the resonator and replace it with an x-pipe and some SS tubing, there is a thread in the ///AMG 210 forum about that. Under heavy throttle you'll pick up a little rumble, but not terribly intrusive.
You should also be able to remove the rear cats and run more SS pipe in their place, so long as you don't mind polluting more and violating federal and probably state law. But you can't do anything with the front cats (or the O2 sensors) or you'll screw up driveability and fuel economy while also triggering the MIL.
So far as mufflers, you're not going to find any inexpensive one that will work well. The good performance ones will cost you many hundreds of dollars, which is silly considering you'll not get any meaningful increase from them.
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!