I have a set of Tein Wagons which are specificly for the Stagea, unlike using skyline ones with usually high spring rates and too stiff. I had 3 different sets in my R33 before I found a good set.
They are 4kg front and 4kg rear, which is pretty similar to most upgraded springs you can buy off the shelf from Whiteline and Kings springs
Have not fitted them yet, so I cannot say how they feel
As Sydneykid has said before, there is more to the suspension than the spring rates. The shock's do most the work and thats why he prefers the Bilstens over most the other "Jap" brand coilovers.
However, the Teins coilovers were brand new and only cost me approx $750 delivered from JP off yahoo auctions, so at half price to the others options available, I thought I would try them.