eight toons, making four pairs, looking for suggestions.

I currently have two accounts, each with 4 toons which will all soon be 70 and ready to start northrend. (One account also has my two 80's but that probably doesn't affect anything) When I made the second account, it was to RAF with a friend so the plan wasn't necesarily to dual box the two when I made them. Which is why I'm in the situation of having all 70's with mix matched combos, since I know someone will be wondering.

I've done some dual boxing before but nothing too long or involved, so I'm wanting to find out from some of you more experienced players what combos you would suggest I use to make the process as easy as possible. The accounts consist of the following:

One:
Druid
Warrior
Warlock
Rogue

Two:
Priest
Mage
Paladin
Hunter

As you can see I have the dilema of having only one melee class on account two. I don't care what spec I level them as, so what specs/combos would you suggest for ease of leveling? Also transfering characters between accounts would be too costly so is not an option for me.

Thanks for your input

1: warri + priest (heal)
2: wl + mage
3: rogue (combat) + pally (retri)
4: hunter + dudu (balance)

at least i would do it this way...