As long as you use the 98 and newer front struts with 98 and newer front springs you will be fine. There is a slight difference before then so that the parts should not be mixed. The rears are interchangable for all years.
The SVT struts and springs will be slightly softer the the early SE struts and springs. Depending on what you expect from your car, you may or may not like the difference.
You may want to check with your dealer before you do anything though. There is a recall on broken springs. You should check to see if your car is involved.
