Jason @Tischer (getbmwparts.com) has a brake kit with everything you need: pads, rotors and wear sensors and pad paste. ~$485 for the kit...
http://www.trademotion.com/partlocat...egoryID=132126
Dan @United has the best deal on Performance rotors... ~$262 for a pair...
http://www.unitedbmwonline.com/bmw-p...5-328-330.html