tire rack oz alleggerita. light. inexpensive (relatively). strong (mine have taken some hella hits up here on our fracked-up roads and I've only bent one so far - bank slipped on a road that climbed out of a river valley and I hit a 4" straight lip at 70 mph - bent the rim but it still held air. hell, kids stole four of five lug bolts off one wheel and I only noticed when I got to the track - wheel shop planed a few mm of the inside and wheel as good as new).
http://www.tirerack.com/wheels/WheelCloseUpServlet?target=runWheelSearch&initialPartNumber=W0183400253B&wheelMake=O.Z.&wheelModel=Alleggerita%20HLT&wheelFinish=Black%20Painted&showRear=yes&selectedRear=W0183700153B&autoMake=Porsche&autoModel=Boxster+S&autoYear=2000&autoModClar=
235 on the 8.5 in front and 265 on the 10" in back really helps turn in and fills out the wheel wells quite nicely.