I have a 2000 BMW M5 (E39). One of my front shocks is blown, so I am getting ready to change the entire suspension. I have an opportunity to purchase USED AC Schnitzer Suspension Kit that has about 40K Miles for $600.00 or BRAND NEW Bilstein PSS Adjustable Suspension Kid (its not the PSS9 System) for $1,000 or KONI Adjustable (DINAN Stage 1) System BRAND NEW for $1,100 I can't decide. On one hand ACS makes excellent system and its $400 cheaper. On the other hand it is USED and if something brakes, it would be impossible to find a replacement. Any suggestions would be greatly appreciated.