Boxing promoters Don King Productions and Golden Boy Promotions will include a World Boxing Council United States heavyweight national championship  a World Boxing Association Fedecaribe regional junior lightweight championship and a handful of boxing’s top undefeated rising stars on the non-televised undercard of the Showtime Bantamweight Tournament Final: Winner Takes All that pits International Boxing Federation bantamweight champion Joseph King Kong Agbeko against undefeated WBC silver bantamweight champion Abner Mares on Saturday  Aug