This is what I'm currently using:
Front:
Back:
Base set: shaman challenge mode gear
Tabard: earthen ring (Tillers could also be an option, although I'm not exalted so i went with this)
legs: ruthless (i dont really like the challenge mode legs, since i prefer a kilt)
cloak: Mantle of patience (the quest where you free thrall from 4 elements or something) - It was kinda hard to find a cloak that matched well.
Weapon: Malevolent gladiator's gavel - I think it fits quite well with the set as it resembles the shoulders
Shield: Wall of Terror - from kel'thuzad 25. The glowing face/skull on the shield fits well with the other faces on the set imo.