You would be much happier with the setup if you buy some KYB AGX's and standard lowering springs. Its about $100 more than the setup you're looking at right now, but the AGX's are adjustable and therefore give a much greater increase in performance. And if you want a smoother ride, you can always turn them down on the street.
Also, look arround for used deals. I got Tokico Illuminas (white adjustables) and ground control coilovers for $400 shipped. Check thepartstrader.com and the classifides forum here to find good deals on parts.