Have you ridden in a car with the SS springs? Compared to your stock springs, they ride very harsh and depending on what you have on there now, may need heavier shocks, too.
Also, have you considered having your original springs re-arched? You could choose your ride height that way. Whichever way you go, get springs that raise your car an inch or so higher than you want. That way you can spacer them down to the height you actually want AND have some wiggle room if they eventually sag lower than you want by removing the spacers to get the height back.