All are great. The question is: do you need more mana and healing power, or more survivability?
I use Flow of knowledge since it's free to get, and since my main is shadow I couldn't yet grab the Malygos trinkiet...
The Battlemaster is probably your best bet, since it gives a nice amount of SP and gives a nice "last stand" effect, but you have to know when to use it at the right moment. If fights are longer then Je'Tze's Bell probably provides a lot of mana, but I think Battlemaster is better, mana will not help you if you are dead.
The Malygos trinkiet looks great TBH, will get one ASAP to test it.
I'm planing to get the Berzerker Deck soon, anyone know how that plays out? It should be better then the crapy Flow I have ATM considering how often I'm focused on...
1 minute cooldown, that's pretty much all I have to say. Or I could further go into how it crits and is affected by talent spiritual healing, have not checked if twin disciplines works but I doubt it.
http://www.wowhead.com/?item=37638 is a GREAT alternative to battlemasters if you are facing alot of melee comps, it's 1.5% to 2% melee mitigation and only short of the battlemaster health gain by 360 hp. It is also free.
Edit: Forgot to add that living ice crystals is off the GCD and unsilenceable.
i curently use the berserker card, and i m glad to say it almost 100 % of the time since it procs if you cast or get hit....provides 105 res rating and 105 crit rating which is kinda nice since it boosts your desprate prayer crit chance but as well gives you a greater chance of getting devine aegis i personaly highly recomend it...