I got my slotted and drilled rotors (front and rear) from rotorpors.com. Decent pricing (don't remember the exact amount), and they are good quality. You can get drilled, slotted or both.
I have had the slotted and drilled for over 6 months now, and they work great. I do notice a slight improvement with brake fade (I don't do much hard braking, though), and everything else was just as good as OEM. I also used Bosch Premium pads (ceramic). I do get a little skeaking from them, but it'* quite rare.
All in all, I like them, and they look very nice. You won't notice too much performance gain from them, but aesthetically they do the car well.