Amer,
Might not be a bad idea to contact Kitfox...... other Kitfoxes out there work perfectly well with the factory designed brakes. On the outside chance there is something else wrong, it might be a lot more expedient to find and fix that rather than do an upgrade. The factory knows the mechanics of the plane very well.
If you have other changes you have made to the plane; like tires, etc, sharing that specific information might help folks in responding appropriately.
Sincerely,