Also, since my guild if starting to do more and more bosses in our 10 man Ulduar, I am curious as to the rumors of "stam-stacking" as the new (old from BC) way of tanking the later bosses and if I should start gemming that way?
Your gear is good but your HP is way too low. Try to get Hood of Exodus, it is a huge upgrade for your head slot. Spec and glyph looks fine. Your hit rating is a bit low and you might see a few misses on taunt withou the taunt glyph. If this causes a problem you could probably switch out SI if this is causing a problem.
Stamina stacking is in my oppinion the way to go unless your healers run out of mana frequently and the raid wipes because of that. I have yet to tank Algalon 25 man but other than than that I tanked pretty much every boss and most of the hardmodes, and healing mana been a problem once for us in ulduar25 or ulduar10, (learning vezax hardmode was a bit rough for healer mana for obvious reasons).