available tire options were:
205 / 255 on 17x7", 17x8.5"
225 / 265 on 18x7.5", 18x9"
225 / 265 on 18x8", 18x10"
M030 is a factory installed option. larger bars front / rear help a LOT; too large in rear will get you wheel spin on tight exits. don't personally know anyone who's done koni inserts, so no clue on the part numbers there. get an aggressive alignment pronto.
great info on the boxster racing board here:
http://boxcar-racing.com/forum/index.php?board=1.0