Healer mods

[krosis]

i recently started arenaing with my 70 Shammy and i was wondering what are some goos healer specific mods for pvp possibly ones that many people find almost manditory

[Taifun]

Only addon that helps me healing are the XPerl Unit Frames, because of their awesome feature of showing only debuffs/buffs I can cure/cast aswell as "Healer Mode" which shows HP lost.

My XPerl Frames looks like:
http://i23.tinypic.com/2il0y04.jpg


Some people like Grid and Clique, but I find it uneccesary in Arena.