Scotty may claim he doesn't know but he is dead right on this one.
Suspension is not one of the things that you want to go cheap on and failures particularly under load are potentially very bad.
Please look at the attached link showing the shock dynos for 4 Raceland setups, 2 front, 2 back.
This is not good and if this is indicative of the quality of these, I wouldn't touch them for a setup that is in any way performance based. Each will respond differently given the same load and the handling characteristics will be chaotic at best.
Suspensions are more than just a bunch of parts tossed together especially if we are talking about building a suspension for performance applications. These are complex systems and they need to be designed for the application. Even if we gloss over all that, spend the money and get coilovers from a reputable manufacturer with an eye to quality and consistency. In the performance arena Koni and Bilstein are pretty much the go-to's. People have their preferences, but setups from these vendors are very consistent shock to shock on the dyno and they can be customized for your specific application via adjustment or revalving.