If you are only tanking heroics a lot of damage mitigation glyphs/talents hurt you more than they help. If however you are tanking raid content you will want them - what I did to solve my mana issues was:

Warning the following only applies to tanking heroics - I would not recommend doing this for raids

1) Respec to 2/2 SA
2) Respec to Benediction instead of Heart of Crusader (does not stack with shammy)
3) Use Glyphed Seal of Command (my preferred Seal for heroics)
4) Drop 1 point of Judgements of the Just (would have dropped 2 points except there was a bug with SoC which made it beneficial to have 1 point in it)
5) Dropped vindication - really is not necessary in heroics nothing hits hard enough to warrant it
6) use Judgement of Wisdom