What they all said
Buy slotted... its even cheaper
If drilled, the holes should be camfered to help prevent stress cracking.
Slots should probably have a camfer also. Sharp edges lend themselves to streas cracks.
Not sure if Pelican has slotted rotors.
http://www.*****************.com/ has them
Vented rotors are what you get on a 911... or 914-6 front brakes... triple layer... radial air vents sandwiched in between two flat rotor discs.
Vented rotors can be slotted or drilled.
- Dave