If you never experienced any kind of coilover and you don't have much of track experience, go with either KW or Bilstein for beginning.
There is forum member who was running B16 PSS10 kit for years now on this forum and he has many trackdays videos posted on the youtube:
I just ordered mine kit 3 days ago, and It should be with me in the next 2 weeks.
But, what made me decide to go with Bilstein over KW are the following reasons.
1.The shocks are Monotube, and rear shock piston is reversely positioned which can have many benefits. The main one is that adjustment knob is easily accessible compared to KW V3 kit.
2. Bilstein is more comfortable compared to KW what I have heard from many F80 owners from European forums.
Overall you can't go wrong with any of these two kits, but I chose comfort as we have bad roads over here and the eibach springs that I've put on my shocks really hurt my daily driving experience. While on track they work perfectly well.
And you will look for the suspension out there, there is just one: Intrax.