Even if you are not a Troll, Blackout proc and Dispel cheesing with SW:P Rank 1 is something worth going for.
This build is designed to be PvP oriented but still viable for raiding. Your main rotation involves Healing Spells, Dispel, Mana Burn, Rank 2 Fear, Rank 1 SW:P, Rank 1 Holy Nova.
If you're getting engaged Fear then Shield & Renew if needed, then get distance as much as possible. Do not initiate a 1 on 1, stay back and move with a group. Low mana-cost SW:P is there to cheese black out procs and dispels. Holy Nova Rank 1 is there to reveal suspected Rogues.
Keep Inner Fire up at all times when fighting physical DPS. If you have time fully buff up yourself. Lower Rank 10 minute buffs helps here too, you want to have some filler buffs so more important benefits are less likely to be dispelled when fighting against casters.
You need a big mana pool and decent HP. 3K HP and 6K mana unbuffed is what you should aim for as a baseline. Spirit is not that important in PvP unless you are fleeing, since fights are quick and you don't have time to wait for the 5 second rule. T1 set is very good for PvP, have all the necessary stats and good set bonuses up until 5/8. Stat priority is Stamina, Intellect, Healing Power, Spirit.
You can experiment with down-ranking healing spells but in PvP it's better to use max rank but avoid high-mana cost ones like Prayer of Healing or Holy Nova. There will be plenty of burst damage and a lot of long lasting CC, you want to heal as much as possible in as little time as possible. If you are the only healer chances are you will be using mainly your Flash Heal, spell push-back is one hell of a thing to deal with. Do not cast anything other than instant cast or flash heal unless you have Martyrdom (Focused Casting effect) on you.
There are plenty of guides on consumables, you don't need to go all out on them for every PvP encounter. Cheap potions like Swiftness can help you tremendously, and also a cheap mana potion is always nice to have, keep the better ones for raiding. Food Buff wise I would recommend Tender Wolf-steak or Monstrous Omelette, the are both cheap and give Stamina, keep the mana regen food for raiding.
This build lacks Discipline's Power Infusion or Deep Holy's increased healing power, but in return gives a versatile tool-set in PvP while still being a viable asset in PvE raiding.