Akinobu Hiranaka, was a LWW champion, Kostya would of beat him atleast. Tszyu was a damn good pro fighter, but even better as an amatuer, why he changed his style as a proffesional I'll never understand. There was also Morris East and Vince Phillips.
i dont know if he was mentioned but sven ottke held amateur wins over antonio tarver, chris byrd, michael moorer, zsolt erdei, and juan carlos gomez