I would recommend a narrower tire. I've got 245/40s on my 17x8 wheel; I could go to a 255/40, but I prefer the sidewall to be flush with the rim. The reason you don't want a 265/35 is that the tire is wider than the rim, and the small sidewall cannot "absorb" the excess width. To get your full contact patch (to use the width of the tire) you'll have to air down a fair bit, and in doing so the car won't handle as well during autocrosses.
Bridgestone's recommended wheel size for the 265/35 is a 9-10.5" wide wheel. They do offer a 255/35 for 8.5-10" wheels, which would be more appropriate. There is a 245/40 that is recommended for 8-9.5" wheels, if you were willing to get a slightly larger sidewall.
If you've got the proper amount of air in your tires, you'll never have to worry about one of these tires coming off the bead. I've had the best results in my few track jaunts at about 34-36 psi, and you're never going to get enough traction to pull the tire off the bead with that pressure. A curb might do the trick, though. 
Bryce
88 GT
