[BYprodriver]

Springs rarely degrade unless subjected to serious corrision. I forget what the difference is between "S" & standard springs but I would verify before installing. Sounds like you are a prospect for whichever Bilsteins come with a lifetime warranty. Put the rest of your money into replaceing suspension parts that are easily accessable while the struts are off. With your mileage they all have worn to some degree & will need replacement soon.