I personally found the hunter team to be a little annoying to play.
Sure you destroy things very quickly, but the pets would frequently have one of them choose a weird target.

One hunter is amazingly strong in relation to one of just about anything else as far as leveling speed goes.
Five of anything destroys the same thing as easily as five of pretty much anything else.
The difference comes when you're doing heroics or more challenging content.

If you go with DK's, they start at 55 and will be 57 or 58 by the time you leave the starting area.
If you go with anything else at all, I'd start some new accounts.
Say two existing and three new. The new accounts only need Classic, unless you want to play Draenei/Blood Elves.
Battlechests are only slightly more expensive then Classic wow, if you're planning on keeping the accounts.
By paying a subscription on the new account, an existing account is credited with a month of play, net cost is even.
Once the new toons are 60th, transfer them to your existing accounts.
Ends up costing you $25 per transfer and a bit for the game, but gets you RAF again, which is far better then normal leveling.

I found 5x Discipline Priests to be a very fun composition. Holy Fire (x5) and Smite (x5) kill anything.
Because you have 5 of the toons you're only using 20% of the mana on each and every toon mana regens.
I had little downtime leveling.

For me, this is a battleground distraction group.
Sit in the back behind a choke point. You can Renew (x5) or PW:Shield, Pain Suppression, Penance.
In short make your opposition extremely miserable.

Another very fun team is all Balance Druids.
They have a lot of power both DPS and multiple HoT's.
Most of the boxing software has some form of mouse broadcasting, Force of Nature and Hurricane are amazing.

A bear is a little more complicated then a Prot-Pally, a tree is comparable to a Resto Shammy.
This combo is basically as viable and powerful as Pally + 4x Shammy, for PvE play.
PvP, you have a lot of power, but a bit less burst and protective totems.





*Edit*
Forgot to add...
Melee are a ton easier then they used to be.

In interface options, enable "Click to Move".
I believe it is in the mouse section.

In keybinds, create a keybind for "Interact With Target".

I'd personally not enable it on your main/healer/tank.
But enable it for sure on your slave/alts, especially if they're melee.

If you run with say 1x Priest and 4x Fury Warriors.
You can click your assist key so the warriors have the same target as the priest.
Now click your interact with target key and the warriors (pets) will all run in to the target.

Anytime the target turns or changes its position, reclick your interact key and the melee will follow it.
Follow is the wrong word. They'll move to where it was, when you clicked the interact key.
You can spam the key, so they'll turn and follow a moving target.

It might be amusing to go with say... Resto Shammy...
In 3.2 Chain Heal is getting a decent buff, 10 yard range on hops.
Shammies are also getting a totem bar to relatively easily drop 4x totems all at once.

So you have decent single target heals, and very strong AoE/group heals.
You have 4 melee in melee range.
Once they're there, click your dps macro's on them.

You could even go with a mixed melee team.
If you're not playing shammy as the healer, say Priest for an example.
Your pets could be... combat rogue, ret pally, enhance shammy and say cat druid.
The pally gets you the option for a Prot build if you decide on heroics later.
Substitute fury/prot warrior for the pally if you like.