First off, your rotors do not "warp"- ask Caroll Smith, author of numerous awesome race car/driving information books.
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
Second, I would say plain or slotted- definitely not drilled. Plains is best for autocross, slotted can help at the track, but honestly if you have the right pads it's far from necessary. I have no real argumetns against slots though. The traits I would shop rotors on are vein/venting design, material (good luck getting any har dinfo on their smelting process!) and then price if there are multiple rotors that satisfied me on the other criteria.
Awesome brake info:
http://www.teamscr.com/grmbrakes.htm
http://www.teamscr.com/rotors.htm
http://www.geocities.com/nosro/abs_faq/
http://corner-carvers.com/altimathread.php.html
http://www.scoobymods.com/forums/arc...hp/t-1122.html
And of course...
Let's talk about brakes! Best tech thread on this board, hands down.