The Corvette C6 Zr1 on sport hard tires is one of my favorites for this race, great acceleration and top speed, it also grips very well once the track dries up. You have to be careful at the beginning of the race when the track is wet, take your time at the corners. Only one stop for refueling and a new set of tires around lap 8.
I also did this race with an upgraded Subaru WRX STI (the newer available model), on sport hard tires, to get as much horsepower as I could and stay below 600pp. It was amazing at the corners but not so at the straights. Pretty much the opposite from the Corvette, but the race was very fun. Only one pit stop as well.