I prefer Grid. Though lately I've been playing with ElvUI which is a complete UI addon basically just altering the default Blizzard one making it cleaner and neater, it has some built in pvp components as well as built in raid frames which are neat.
Not sure how you heal, do you target on raid frames manually then use keybinded spells, or use something like Clique which allows you to bind spells to your mouse buttons or use them for modifiers, or are you using mouse over macros that cast heals when you hover on the raid frames?
If enough people want it I can make a healing add on section, in the meantime if you look on Tankspot, their priest Aliena has a great tutorial on Grid and Clique and how to set them up. Grid is so customizable you can get it to tell you just about anything and make it look however you want. It has some mini addons that work with it you will definitely want Grid Mana Bars. For while I was rolling with a hot pink grid frame on my pally lol. I also like it because I prefer small raid frames that keep my screen uncluttered and Grid can be set up to be very small and clean.
Vuhdo is also an option, again highly customizable and maybe not quite as complicated because it doesnt require the additional components Grid does, it also doesn't(last i knew) allow you to target players like Grid does, only heal on mouse over/click which is why I prefer Grid. If you use something like the Razer Naga Mouse with the 12 side buttons this is a better option.