S-Curve Tire wheel combo

[3kidsnotime]

I have already purchased some tires in 17 inch but we dont have to use them on S-Curve, So if we go another size we will just calculate the cost of what is used on the car, I would like some input on what everyone thinks, Now the car is going to the track so we need to remember that also. What tire seems to work the best for our application and size? What size wheel do we want to run? if needed I will cut and split the inner wheel house to the frame we can gain some space if needed in the rear.