KMS are just rebadged Supertech valve springs. Call supertech they will tell you the same thing. Now Supertech recently changed their retainers so i dont know if KMS uses the same retainers or they are using the older ones.

Personally i would get the SKunk2 valvetrain and PRO1s, you dont need PRO2s unless you have 2.0l 12:1 compression. Skunk2 NON PRO valvetrain (which is fine for PRO1s) is really inexpensive