I was thinking about the ART ones as well, but one of my trusty mechanic (who has a racing license, and a modified 944 Turbo) recommended against slotted rotors, saying that they will chew through pads like there is no tomorrow.
He seems to think that cross-drilled is the better way to go, but I'm not convinced of the benefits of that either.
I was going to get the el cheapo Aimco rotors from Autozone for $61/piece, and get them cryo-treated for approx. $30/disc. But being the el cheapo that I am, and that I got lucky, hello, Bendix rotors.
VK