So where can I find the rules about what equipment is needed

Helmet has to be Snell (2007 I think). Some of the cheaper ones aren't, be careful. I ditto what everyone else says and recommend getting a helmet even if the regs don't require it.

My local track says 7.22 in the 1/8th for roll bar, but they're an odd bunch. Every quarter mile track I've been to says 11.49 but your mileage may vary.

I'm in the same spot you are. Fortunately, it hasn't been a problem yet.

Steve