Jimmy,
1. Those are Lincoln brakes in the front (i.e., brakes used on the big Lincoln in the 1960's). It's due to the rules. Cobra Automotive sells a kit. I think the front rotors are 11" (15" wheel). Yep, the rear disk is a Corvette/PBR.
2. Yea, the smaller holes just didn't work. Cobra Automotive also makes the kit that includes the intake, hoses, brackets. The caliper also has a bracket that the hose is clamped to (very effective).
3. Tires are Hoosier TD (bias belted) 225-60-15, Hoosier TD 25.5-8.5-15, or Goodyear Blue Dot 6.00 X 16 by the rules. No radials allowed.
Some guys use a Brembo brake (a Porsche design), the same air duct, and larger rear tires (Goodyear 7.00 x 15). That bumps up a class.