You need the full coilover kit, not just lowering springs or "sleeves". This will make your car ride like stock, IF NOT BETTER, and still have the ability to adjust the ride height. You can get a very good set for around $650. You can go with higher end stuff like TEIN, or Skunk2, but you will pay $1,200+ for them. Look on Ebay for "omni power coilover" and you will find what you need. If you go with a spring, then you will find that lowering your car more than an inch will cause you to buy new struts every 2-3 months, which cost $60 each. The sleeves are also the same way, busting struts all the time. Plus as an added benefit the coilover installation is VERY easy. you just remove the factory strut/spring assembly and replace with the new setup. It takes about 30-40 minutes on your car to do this. The springs, and sleeves require you to buy/rent a spring compressor and break down and rebuild the strut/spring assembly. This takes 45 minutes on each wheel.