There are many good builds, but find what works with your play-style. I run with 5 crit rating and H4P2 regardless of whether I'm solo or grouped up. I tried 6 crit rating, which a lot of people like, but found the extra health to be more valuable over topping off crit rating.
With this build, you can run Aura of Command and Commander's Stance in groups and heal like a boss. Make sure to toss out shouts between heals and Power of Fear (the purple spiky aura) will always be up and you'll constantly get big heals for your whole group with Quit Whining and Fight without having to wait for skill induction.