Planning to 5box. Which toons to pick?

[Ualaa]

You could go Dreamstate on the druid, which is a hybrid Balance/Resto build.
Deep enough in Resto for Swiftmend, deep enough in Balance for Moonkin.
Extremely mana efficient, but lacking the talent based AoE's of both trees.
As the only healer in a group, this is not a good idea.
With a priest for heals...

Priest is primary healer, has strong AoE heals.
Dreamstate has very good single target dps, which you're doing boxing anyway.
You still have Hurricane on the Druid if you want.

You then have the option to roll HoT's when needed or have a DPS provide fairly significant single target heals.

I absolutely loved dreamstate in burning crusade.

[Diwa]

Always have a warlock in your team for convenience.

[Ualaa]

In reply to the original poster, selecting from:

1 x 80 Paladin - Soap
1 x 80 Druid - Ghør
1 x 72 Shaman - Ghur
2x 70 Shaman - Zubwan & Zubtres
1x 70 Rogue - Wazza
1 x 70 Mage - Frizza
1 x 70 Warrior - Shaiah
2 x 70 Priests - Cian & Cixi

If you have your heart set on two teams, each will need a tank, a healer and three dps. You have a lot of healer and dps options, but only three tank options.

You will need to use the Click to Move and Interact With Target, because of the Rogue.

I'd actually go with a predominantly Caster based group 1, and a predominantly melee based group 2, just for the variety. The pally is the best tank for AoE and a caster based group (imo), so I'd split them like this:

Group 1:
Paladin - Tank
Mage - Frost
Shaman - Elemental
Shaman - Elemental
Priest - Discipline

Group 2:
Druid - Tank
Rogue - Combat
Warrior - Fury
Shaman - Enhance
Priest - Holy

Really, its personal preference, just about any configuration will work, provided each group has a tank, healer and three of the dps. I'd personally go with Click-To-Move & Interact-With-Target, entirely in one group, to make it a bit easier on yourself. The two groups will play very differently.