Mark, aftermarket brakes are not a requirement. Upgrades are just a personal choice. However, dual circuit systems are required.
In many classes, the use of stock brakes is required, with the exception of friction material. In other classes, the only restrictions are to size used. I am <u>allowed</u> to convert to rear discs on the Sprite, for example, as long as the rotors are no larger than the fronts.
Jeff