You are thinking of the Coldain monk armor I think. You need ancient leather leggings for Kael armor. You probably got those leggings IN Kael, but of course that would mean that they can't be the pants used for Kael quests. :)
Can someone please post where I may find this NPC. I got a pair of eroded leather pants, and am working on getting gems, and I wanna know where I turn in my stuff.