Here is a list of where to get them by zone. I made this list for my own quick reference and thought I'd share it here.
If you want to see the stats go here http://aoc.is-better-than.tv/
It's a great site but just a little annoying when I'm in a K6 and wondering if anything might drop for my class.
Abyss of Kun Whu
-Shadow's hands
-Wolf belt
Cavern of Malice
-BB belt
Celestial Necropolis
-Shadow's shoulders
-Wolf hands
Coppice of the Heart
-SC shoulders
Den of the Crowmen
-BB hands
-SC belt
Enigmata of Yag
-Book: Impede Life 2
Jade Dugout
-Scholars belt
-Book: Slow Death Strike V
Kang Pagoda
-Scholar hands
-Shadow's belt
Palace of Yun Rau
-Wolf shoulders
-Book: Grim Corruption V
Pillars of Heaven
-Scholars shoulders
Reliquary of Flames
-BB shoulders
Vortex of the Storm
-SC hands