Roush #1 Jody Run &Gun has 4 different classes. First time beginners, Street, Prepared, and Pro. There is 4-5 classes in this, 4-6 cylinders, V8 small block, V8 small block with power adder, Big Block, and Big Block with poweradder. Tires are the limiter for Street and First time beginners. As far as what tires you want to run we have cobra guys running 15" to 18". IMO alot of picking the size depends on your experience. Most of us started with 15" BFG tires,
which are cheap and you learn to power slide your car and control it. Then after you are infected you will work your way up to bigger brakes, 17" wheels, better shocks and harder springs.
The only cure is more track time.
Jim Yale should be able to get you started with a good setup for the car. Just have to remember that the setup on every track is different. 2 safety points I will make and you may have already done. 1st get a nomex helmet and driving suit if you are going to get serious. 2nd is make sure that your roll bar is 2" above your helmet with you in the car. A good roadracing seat also like a kirley that is mounted well. The springs and shock will be different from your street setup. Looking forward to seeing you at R&G. Rick L.