Tires of 15" for "competition" desires are very limited as well as sizes are limited. You'd need to look at your chosen club's rules to see what they allow for certain classes. Then, decide if you want them streetable (and to what extent.. daily, wknd, rarely?), or else, trailer them and mount at the track. Hoosier tires are stickiest DOT 15" tires out there, but they truly aren't intended to drive on the street/hwy, though some ppl do just to/from competition events on the wknds.