First you will need to inspect the suspension bushings, they wear easy and on a ten year old car they are most likely in bad shape if they haven't been replaced already. Front lower control arm bushings are a common problem, inspect your rear suspension links also. For springs I would recommend either H&R or Eibach. H&R's cup kit tends to be a little lower than the Eibach pro-kit so whatever you're preference is for ride height would determine which brand. You could upgrade to C43 sway bars front and rear, they are the same as CLK55, and they are the biggest available for the W202 chassis as far as factory parts go. Of course, eibach and a few other companies make sway bars also but are more expensive. I would also recommend visiting club202.com, it's a website dedicated to the 202 chassis. Good luck!