Best bang for your buck:
Z1 2 Piece Akebono Front Rotors
The slots on the rotor are to remove gas build up that is generated under heavy braking.
HowStuffWorks "Drilled Brake Rotors"
You can run with drilled and slotted just fine if you don't drive at 10/10th's all the time. If you track regularly then you should spring for slotted only.