Spirit's Stength Build - Armor

Which armor bonus is best for a Rt/A spirit's strength build?

I'm looking to buy a factions armor set, so I'd like to know what bonus works best before I purchase it.

Thanks!

I would think that the armor that gives +armor while affected by a weapon spell because for a spirit's strength build you have to have a weapon spell for it function properly. (Sorry the name of the armor slipped my mind)

Edit: The armor's name is Emissary's Armor.