If you plan to do any autocrossing with your car, you can't use slicks in SCCA classes, unless you're running a Modified class, and that's not going to be very much fun for you.
However, you can run R-Compounds in any class except Street Touring and Street Modified.
I'm running G-Stock this year, on a set of 205/50ZR15 Kumho Ecsta V710s. I'm also picking up a set of the Kumho Ecsta XS. Tire contingency FTW. The Hoosier A6 is a great tire, but the Kumho wears better in my experience. The Kumho is about 99.5% as sticky as the Hoosier and about lasts about twice as long, especially on a light car like an Integra.
My performance driving mantra is actually taken from college basketball coaching legend John Wooden. "Be quick, but don't hurry." I say that to myself shortly before getting to the start line--reminds me to be patient where I need to be, and aggressive where I can be.
My full GS setup is this though...
Koni Sport shocks/struts
Kumho Ecsta XS or V710 tires (depending on weather, the V710s don't stick worth a crap in the rain)
Brembo Rotors
Hawk HP Plus pads
Oil pressure gauge
Optima dry cell battery
I've got a line on a nice looking bolt-in roll bar, but I don't want to attract THAT much attention on the street....I'd really only use it as a harness bar anyways...