World of Warcraft Arena pvp, help please anyone?

Yeah I have a holy pally and it just feels like they're one of the worst healing classes (in my opinion). And in the quickly approaching patch 4.2 almost all of a holy pallies healing spells are going to cost more mana so I'm not using my pally again probably for awhile, holy priests are the most popular healers i've seen so far, only thing that sucks is they reduction on how long PW:S lasts. I healed on a shammy pre cata (havent played him since though) was REALLY fun and he was a kick *** healer so i think you'll like having one. And as for gemming the shammy i'd go: spirit, int, and crit.