I have neither cross drilling or slotting in my rotors in my race car. What looks cool is very big brakes.... slotting and cross drilling comprimises the strength of the rotors...may look sexy but I wouldnt bother...if your brakes are being used in a way they are continually overheating the only solution is greater diameter rotors and calipers to suit. I used standard stanza slotted discs on the 1200 coupe race car and never NEVER had a problem with fade. I did however go through a set of pads every race meet or practice day. I could live with that as they were only $30 a set. Why have I got got Willwoods now??? good question because the car I bought came with them.
I would say for the street you wouldnt need to go bigger than stanza even with a CA18DET...you just wouldnt hammer them like you do on a track.