I ran a yamaha sit up for many years with NCK. Tires will not be an issue for your world formula. You can run several races on a new set. You will find that too much grip in the lower hp classes actually binds it up and slows you down in the corners. You want the kart to be as free as possible to keep the rpm’s up.
Good luck. Most of all have fun and see greens and checkereds.