To do these quests you need 3 components. The anadorned armor, 3 gemstones, and faction.
The unadorned chain armor is a no-drop, no-stat, component of the Skyshrine quest armor. It drops in Temple of Veeshan in the Hall of Testing. This is a high-level (55+) dungeon off the western wastelands. Any lower than 55 and you simply won't have enough magic/poison/fire resist necessary to survive.
Then each piece of armor needs 3 gems of various types. These are random drops off mobs in Colbalt Scars, Velk's Labrinth, Dragon Necropolis, Icewell Keep, to name a few.
The final component is to give both the chain armor and the appropriate gems to a specific mob deep inside Skyshrine. You need to be on ally standing in order for this mob to do the quest at all. How do you raise the standing? Simple. Kill giants. Lots and lots of giants. And the closer you get to the giant's arena in Kael Drakkel the more adjustment to the faction. I wouldn't even think about it until your 35 for the easy stuff in the Great Divide. Inside Kael Drakkel? 50+ for the halls and 55+ for the arena...in large groups that is.
You can buy the gemstones, you can even "buy" the no-drop armor by getting someone to multi-quest it for you. But you have to be ally with the Claws of Veshan (dragons) in Skyshrine in order to turn in the components and recieve the quest armor.