Best ifs kit? rms, hdk, gt suspension, or magnum force?

i have hdk kit in mine bb dart i have have tried 500lb 450 and 400lb the 400 gave me the best ride and performance with 10'' coil over shock 440 with iron heads
turns out , I have 500 pound springs on my front coil overs. have been advised to 350 pound springs. trying to pay w/ paypal. dam paypal is f/u, won`t work ! if anyone needs 2 500 pound 10" long, 2 1/2i.d. springs , mine are for sale ______--c h e a p ! dirt cheap !