I am thinking about respeccing my tanking spec to
Talent Calculator - World of Warcraft

My armory: The World of Warcraft Armory

My question is: How suitable is my spec and gearing/enchants/gems for doing both Boss MTing and OTing in Ulduar 25man. I'm also wondering about the merits of purely using stamina gems like I currently am.

Feedback on both my current/prospective spec and my current gearing is much appreciated. Thank You.