I'll take a stab at this. For men, the shortest gold medalist I'm sure is Joseph DePietro WL 1948 gold medal in bantamweight. He was 1.40 metes tall. The tallest is Arvydas Sabonis BB 1988 then bronze 1992 for listed at 2.21 m.
For Women, the tallest I'm sure is Uljana Semjonova ( nationality) BB 1976 and 1980 listed between 2.10 and 2.16. The shortest is Mariya Filatova Gymnastics 1976 and 1980, 1.36 meters tall. Filatova is also likely the lightest listed at 30 kg.
For men, the heaviest gold medalist is probably Leonid Zhabotynsky 1964 and 1968 WL listed at 163 kg. The heaviest woman is Zhou Lulu 2012 WL at 133 kg.
Actually, the shortest and lightest men's gold medalist may be the unknow cox of the 1900 pairs event, thought to be around 11 years old.