FK Front Springs rates are 400/lbs per inch. The rears are progressive and are definately softer but nobody knows the rate. Probably in the 250-300 range, but that is just a guess. FK struts are beefy!! They look solid. Of course only time can tell. But they definately appear to be very solid, and the install was cake!! The rear adjustment though is a bit difficult to get at. It looks like you might need to take the spring off to adjust the height
The KW's are nice, quality looks to be good (stainless steel throughout!!). The spring rates aren't known, but I would be it would not be a problem. Unfortunately I do not know anyone with those. But Oscar Jackson pimps them like crazy, if that means anything!!
You might also want to look into the new Intrax ARS coilovers. They look to be built well as well and probably pretty firm. But once again they are an unknown. However this set you can get for 1100 and you get adjustable ride height and one-way adjustable damping.
Then of course the H&R's are awesome across the board, but i would only buy from FocusSport if you want a lifetime warranty!! Good Luck!
I drove a ZX3 with the KW coilover setup on it and it cornered very flat and I liked it alot. The only downfall to the car that I drove was that the tires did not grip up that well and when I hit a corner at speed, I just understeered alot. The ride quality was not at all bad either. I myself am going to go with the H&R's but I have considered the KW's and almost bought a set over the summer.