Great find!
Run Motul RBF600 fluid and change to race pads for the track. Porterfield does make pads in various compounds and manufacturers for both the front and rear of the 335i. They used my car's pads as templetes
You can run Porterfield, Raybestos or Hawk in any of their compounds. Just give them a call.
If these modifications still don't provide enough consistant braking at your events, then its time for a BBK. The Stoptech guys are great and they used a previous car of mine to develop a four wheel kit to bring to market. If you live in SoCal, you can stop by their factory. Like I said before, any of these BBK's will be fine and won't be a "wrong" choice. Just make sure the brake pad manufacturer you want to use makes a pad for the particular caliper.