Any Neck slot item he can get. He has very little Will and his Fortitude is not great either. If he runs into a warlock or some of the lower-level controllers he may be in trouble. A safewing amulet or catstep boots would be especially good, because a lot of the Will attacks I'm worried about cause forced movement.
A duelist's weapon or resounding sling can create extra opportunities for combat advantage.
I am more interested in playing an aggressive style of play so not looking at any defensive options (I know silly but intend a ranged start to encounters, then leapiing in to mellee after a few turns, and leaping out when it gets too hot.
Your sugegstions are along the lines of what I am thinking, how about these Iron Bands
Iron Armbands of Power are great for damage boosting, boring... but great. For armor, I would suggest Elven battle Armor. With an encounter power of +2 speed and a property of +5 to saves versus Slow and Immobilized, it should preserve your ability to move in to good positions for sneak attack. For heroic tier weapon enchantments, duelist is one of my favorites.