There isn't a lot of choice if you're looking to match the lava texture, most lava-y things being shammy only. The recoloured Earthfury set has the lava theme going, but it's black with orange lava. To match the colour of your Surging Mana shoulders, (blue with goldish trim) you could go with pieces from the Bloodthirsty Gladiator's Chain set. I also found these pieces that match the colour palette:
Stilled Heart Mail Set
Weapons: Rifle of the Platinum Guard, Prison Warden's Shotgun, Sen'jin Beakblade Longrifle(Horde), Felglacier Bolter.
Good luck, happy mogging =D
(sorry it won't let me put links in yet)
Try using the hunter Tier 5 if you are looking for some blue, I used http://www.wowhead.com/item=49844 when I was using the Tier 5 set, goes well with my NE hunter's blue hair