I have a CKS Coilover set up removed from a 2008 335i sedan. The CKS shocks have less than 10k miles on them and the upgraded Swift springs are only 6k miles old. Swift springs are rated 400 lbs for front and 800 lbs for rear. This set up is in excellent working condition with no problems or damage whatsoever.
Here's a link if you want more detailed specs:
http://www.**********s.com/CKS-Suspe...90-E92-E93.htm
This kit sold new for $1,950.00 and the Swift springs were $400 new.
Asking $1,500 shipped for the whole kit.