These two links discuss transmogrification options for leather armor sets in World of Warcraft. The first link shows pictures and descriptions of several stylish leather armor sets for different classes. The second link allows searching for specific rare leather armor items from past expansions that can be used for transmogrification appearances.

1. http://wowroleplaygear.com/2010/01/04/stylish-leather-sets/
http://monsterwow.com/quest.php?name=old_items&quality=4&material=1&slot=0&requiredlevel=80&q=+Sain
t&search=Search