Do some research. As Beemer Guy said, save your money and get better pads. You will see very little benefit from slotted rotors. I've owned slotted, cross-drilled, and slotted/x-drilled rotors at various times on various cars. I never saw a benefit with any of them and the cross drilled rotors DO crack.
If you have the money, pick up a set of Brembo GT's. If not, get better pads and enjoy the benefits of less dust, better initial bite, and better fade resistance.
Drilled holes all the way through can weaken the rotor and make for cracks. "Dimples" - holes not all the way through, can be very functional for heat dissipation, but probably not needed unless you are tracking the car. Slotted with dimples will be my next brake rotors