Personally... Ground Control coil overs in the front. Pick your own spring rate but most guys go with the 500lb springs. Combined with the correct shock (Koni SA) the ride is not that bad, actually better than the Sportlines (mine are STILL for sale!!). PLUS, you can adjust the ride height to whatever you want.

I went with 125lb springs in the rear. Not too stiff when combined with the Bilstein HD's.

Alot of the apparent stiffness "feel" has to do with improperly matched springs and shocks. Get the right combination and have the best of both worlds.