Hi Kat,
Just happenned to saw your post and I am also looking for a Bilstein Kit. So this is what i know.
B6 = sport (yellow) shocks for non-lowered car
B8 = shortened sports (yellow) shock absorbers for lowered cars.
B12 = Bilstein tuning kit. This is basically a sports shock absorbers with lowering kit. It comes with 4 B8 shocks and 4 optimally paired bilstein springs (but made by eibach).
The B12 is your best bet if your car is not lowered and you want to lower it. B12 enables your car to be lowered by 35 mm in front and 20 mm rear. You also get the upgraded performance from your sport shock absorbers.
Alternatively you can buy the sport shocks and paired it with eibach pro kit. A lot of people do that. But if you want best result the B12 is still a better choice.
So far I have been asking around. Most places including Obermair, Stuttgart, Bavarian Auto etc. do not sell the B12 BTK. They sell the sport shocks paired with eibach springs.
I will post a picture of what a BTK is supposed to look like. All 4 shocks comes in one single big box.
Hope this helps.
