That's a hard question, different drivers like different set ups.
I'm currently at -2.0f/-1.0r camber, effective zero toe front and 3/16 toe in rear, max caster and still a little left on the lowering bolts (still running stock shocks). This is running 295r/315r V710s. It was good enough to win the SCCA Atwater Tour event at the beginning of this month.
Others, including guys who have been winning at the national level for a long time, run more camber and also run a little toe out in front and more aggressive toe in rear. Again, a lot depends on your style of driving and what makes you most confident in the car.
I'm running -2.0f, -1.6r camber, 1/8" toe in in the rear, and 1/16" toe out in front, and as low as I can go on stock bolts with the car properly cross-weighted and balanced. I'm still running street tires as I'm still a rookie, but as far as car setup, this feels great to me. I got this setup from a guy who's placed in the top 3 at Nationals a couple times, and it's the same as he runs on his SS Z06.