Plate pieces for this Quest drops in Temple of Veeshan. To my knowledge in West wing and Northwing.. Halls of Testing drop the dragon quest armor.
When you receive a piece of plate from ToV you can bring that and 3 gems(dependant on the item you want) to giants in Kael.. hand in the plate and gems, and you receive the Kael quest armor..
You need Ally with Kromzek to do the quest, Kromrif and Tormax should be dubious atleast to stay safe..
Currently I have the Shining Greaves and won the Shining helm last night.. :)