what is the best all around group to do horics with

[Ualaa]

For me, the best set up is:

Paladin tank
Destruction warlock.
3x Elemental Shaman.

It gets me enough healing for any encounter.
I usually go Warlocks/Shaman (Kings), Paladin (Sanctuary).
Drop 3x Healing Stream totems as part of my totem stomp macro (or can go with Cleansing Totems on a key).
Earth is staggered Tremors (staggering Call of Elements/Call of Spirit, not individual totems).
Fire is Totem of Wrath x3, Air is Grounding x2 + Wrath of Air x1.
I also have a resist set, where Fire Resist, Cold Resist and Nature Resist are available.
I use Runescrolls for Fortitude and Drums for Mark of the Wild.
If mana were an issue, you could use Drums for Kings and then bless Wisdom on the other toons.

Pally is a simple 96969 macro.
Shammies and Lock are a basic "click".
On bosses I have the lock do Curse of the Elements (by moving that into the clicked buttons).
On AoE, move CotE out and drag my Seed of Corruption in.
On trash, its basically neither.. Immolate, Conflagrate, Chaos Bolt, Incinerate sequence.
Or sometimes the CotE is still there. It's usually CotE or SoC as the first click.
Shammies are FlameSh, Lava, Chain L, L.Bolt.

DPS is one click.
Tanking is the same click.
Heals are by clicking on the repeater region (IS Boxer).

Pretty easy to execute.
Quite a strong composition.

One thing that helped enormously when starting.
I ran dailies with the team.
And spent the gold on my tank, to gear up a bit.
Going from 21k to 27k took many heroics from very hard to a breeze.
I'm sitting closer to 38k now on the tank, but that's a mix of badge upgrades added in.
The tank is the key, for just about everything.