CS is super easy and simple, copy the setup on our car which is just our Race muffler, Koni Sport shocks, Karcepts front sway bar, our most stiff Penske racing rear bumpstops, good alignment and ready to have fun. You can spend a ton more on custom Penske shocks but we won our local region season last year here on the Koni and the SCCA Tour event too. Thus, my suggestion is do not overthink this, the whole point of this class is keeping it simple and formula laid out above wins.
No big brakes for CS, no point in doing anything for CS on brakes with possible exception of pads you like more and yet we won our season here last year on 100% stock brakes. If you using a lot of brakes in autocross... you are going too slow. It's about going and not about stopping. You are racing a momentum car, which means you use as little and as brief an application of brakes as possible. And since we are doing just 1 lap at a time the bigger thermal capacity of big brakes is pointless anyway.
Cannot do coilovers for CS, you must stay on stock springs. There is really no substitute for starting to read the rules yourself. Just google SCCA National Solo Rules and you will have the link to it and perhaps it takes 5 minutes to read the entire CS section that starts on page 73 of those rules.
We use a set of our 17x7 Storm with the class leading Yokohama A052, size 225/45/17. Note that will rub the plastic fender liner at full lock, if you care about such things (we don't since you don't drive at full lock).