+1 for the B12 kit. Really good bang for your buck purchase. Completed the install with two friends along with Whiteline RSFB and the difference is night and day. Body roll is reduced, the car feels composed and controlled.
My recommendation is to remove the stock run flats soon after if not before the B12 install. The ride is quite harsh with the run flats still on.
Best price I could find is here:
http://www.ajusa.com/Bilstein-46-180...it-acb089.html (Tip: Ask about drop-shipping direct from Bilstein)
Here are some pictures of the kit, Bilstein makes high quality products and it shows.