13" brakes cover more surface. as for drilled and slotted rotors, what does the drilling really do? You put holes in your rotor. Typically I'm okay with slotting them, but drilled for a street car is a little to far. Your doing nothing but adding eye candy. Your taking away surface for the cooling that your brakes will never get. go 13" with slotted rotors. get some red calipers or blue to stick out from the black and your set.