Pagid, the Porsche Motorsport pad is the real deal; the street compound to use is their "Endurance" pad (otherwise known as the Yellow Pad), called RS19; there's been an update and there is now a different and better compound RS29 I think. I've also used Porterfield R4-S which stops great. The R4E stops even better and the R4 stops so hard, it makes utterly mindblowing stops but they will be hard on the rotors, in the same way Hawk Blues are hard on rotors.
For further objective information, look in the October 2011 edition of Grassroots Motorsports where James Clay, the owner of Bimmerworld tests 7 different pads. The write up is quite god, and it's a good read.