is the build that I would recommend. It is Heartwood's spec.
The Improved Sunder Armor reduction in rage cost applies to Devestate as well as SA. Over the length of a boss fight, that is a lot of extra rage that can be put into more threat generation.
In a boss fight, you are not going to be changing combat stances. At most you will charge into combat with ber. stance and then switch to def. stance. So TM is not a good use of talent points.
Take the points from improved charge (which you will use once in a fight) and move them into improve heroic strike. HS is a rage dump, but it can also be a rage efficient rage dump. You'll use HS a lot during a boss fight, so these points are very well spent.
At the brink of danger I stand. Clad in armour, shield and sword in hand.