GC's are sweet springs, and my buddy has skunk2's on his GSR on stock dampers, and the ride is actually pretty tolerable. I'd go with Koni yellows as well, 8-way adjustable will go nice with adjustable springs. If you go with yokohama I would highly suggest the AVS sport or the Parada spec-2. I had paradas on my SVT contour a couple of years back, and they were f'ing sweet.