I beleive some people are using springs from the Proceed. I don't think you will really need any more sets of springs then the kit and the extras you have already bought. The silver are softer and the gold are harder then the kit springs. I use Black fronts and Silver rear with diffs front and back. With a solid front axle Silver front and Black rear is what AMG runs. You could also tune using shock oils and different shock pistons. The car really is pretty easy to set up for good handeling. It has a wide sweet spot.