I mentioned this to Ryan(above), because he is working on something for his 1st gen. I will make a thread here also about the brakes, I have one on the Expl....X.com forum. My idead started as using stock rotors and calipers, and I ended up having to make two piece rotors to get the right offset.
There are two other options besides this. The Saleen Explorers came with 13" brakes(Alcon), and were all recalled because the aluminum brackets were breaking. A member in Norway still had his, and remade the brackets in steel. Unfortunately the calipers and rotors are $1800, as special order parts. The pads alone are over $250, so actually only one person has assembled them, for his XP8.
The other option is a revival of a kit that EE put together on their first X-Spec prototype. Another member talked them into making them available. That setup uses stock Corvette rotors, cut to fit the 4WD hubs, and stock PBR calipers. The price wasn't official that I recall, but well over $1500.
These brakes that I have built I have over $1200 invested, plus quite a bit of labor. I will help a few serious people to have them, I'm aiming at $1400. I have ordered three pairs of custom hats, and one pair of matching rotors. With these I will have the bracket dimensions confirmed, and have a couple more pairs made. The calipers I use(stock rebuilt Corvette 65-82 powder coated with pads) have to be relieved slightly in the throats. I could let someone do that for themselves, but I already know how much trouble and time it takes. That is part of the labor I have to invest. Check out the other thread, and get back to me. Regards,