You have to ask yourself how much lower do you want to go? Also, if comfort is an issue? Generally, the lower and higher spring rates you go, the less comfort. Springs can lower your car by 35-50mm, however, your stock shocks won't last as long. Coilovers drop about the same, if not lower and the benefits are written in the post above. I'm currently using BC Coilovers. Don't forget, adjustable dampeners & camber. :D