Mort Geller of Hollywood, Fla., 68, a respected international wrestling official, died July 25 in Florida of congenital heart failure.    Geller was the 1999 USA Wrestling Official of the Year, based upon a career of achievement and service as a referee. Geller was involved in wrestling officiating for 30 years and achieved the highest rank as an international referee.    He worked in the Olympic Games as a referee representing Israel. He also worked numerous top international events across the world on many levels.    Geller received the Phil Portuese Award for his work as a teacher and mentor for young officials. According to U.S. Olympic Wrestling Officials Association President Rick Tucci, he was a valued counselor for him, as well as the rest of the U.S. officials. Geller was originally from Illinois.