Bring the Skin of the Great Sandworm, 2 Idols of the Sun, 5 Silver Scarabs and 5 Bone Scarabs to Kandrostrasz inside Ahn'Qiraj. You must also attain Friendly reputation with the Brood of Nozdormu to complete this quest.
Yes... the worm's skin will make for an excellent protective layer. Combined with the strongest parts from the Qiraji we've destroyed on our way here, this should make for a formidable piece of armor. May it aid you in facing the unspeakable horrors that await inside!