I justed had the Eibach pro-system installed and I like it a lot - The handling improvement is huge over my weary stock setup
I had heard that Eibach Springs (pro-kit) with Bilstein HDs or Koni's was the better way to go, but I gotta tell ya, this setup is very nice. Go the Pelican parts (
http://www.pelicanparts.com) BBS, and read about the suspension setups there - search on Eibach; you will find that many people use the Eibach springs, but no one posted anything about the shocks and struts.
I figured they had to be better that what I had, and its defintely true. It was also a great deal - cost me $700 for the kit, and $280 for installation; I also had the rear shock mounts replaced as well (highly recommended).
The ride right now is firmer, but still smooth. I took the car through some twisties and it was amazing how much more confident the car feels - just soaked up bumps and ireguarlities and maintained composure the whole time. I felt glued to the road. Even when I pushed it too far and started into oversteer, the car still maintained composure and felt confident - just very controlled the entire time. Very nice...
I have a feeling that the Bilstein setup will be more of the same, only better/smoother/more expensive.
Hope that helps..