i don't get it i have 04 GS300 and tirerack shows only pro-kit under suspension category . Now when i change the car to 02 GS300 i have all kinds of different suspension parts. as far i know there isn't any difference in 02 to 04 Gs300 unless im wrong.

They should be the same, our fitment info for suspension is taken directly from the manufacturer. But I have gotten confirmation from both H&R and Bilstein that you can use the items listed for the 02. Eibach should be listed for both already.