D3vin

I was searching for a set of new tires in Tirerack and I came across some Eibach Pro kit or Pro-System kit. I want to know how much does the pro-system kit lower than the pro kit and performance wise, would it be better than Skunk2 coilovers in terms of performance and comfort combined. The cost of the kits are about 4-5 bills and I don't know whether I should upgrade from stock shocks for my skunk2s or I should just get that Eibach kit. Sorry for my English.