I'm doing so more research on parts needed... apparently Brembo makes a special rotor for the base Boxster to use the S rear calipers. Problem is nobody knows where to get this mysterous part. Can't locate this on the Brembo catalogue webpage either as it only shows front rotors for the base boxster.
What brake upgrades do we have for base Boxster?
http://www.boxsterforum.com/forums/showpost.php?p=23054&postcount=3
http://www.6speedonline.com/forums/boxster-cayman/112389-brake-upgrade-2.html#post1578029