springtech springs?
springtech springs? 
I'd ask the seller a question on ebay and if they can tell you the spring rates, then we can help you, otherwise I'd not consider them if they are one of those "mystery" spring rate springs, because when you need proper shock valving, the spring rates need to be known, otherwise problems many problems will arise after you install them.
ive got those springs on my car, had them since july, and i dont have any problems with them at all. i am also running the stock deCarbon shocks as well. i jsut got them bc they were so cheap, and have no complaints as of yet.
That is until you replace the stock decarbons with something properly valved. I added springs like that at one point (before my current coil-over setup) only to eventually discover that the stock decarbons became prematurely worn.
