If your looking for replacement springs for whatever coilover setup you choose....only look at the Swift Spring line up.
www.swiftsprings.com

 

I seriously doubt that the cost is justified if you've already got springs, and even if you're buying new ones, the swift are so much more expensive, and for what really, a little extra travel and less weight? Seriously, how often does one have troubles with coil bind, and it's only half sprung weight, you won't notice the weight difference.