I like the first team mainly due to Paladin/Warlock, making 2 lvl 40 mounts free with more money for the others.

However it sounds like, so far, that instances are easier then people 'recall'? I've seen a few videos on Youtube supporting this, so therefore if you plan to level this route, money may not be an issue.

The other main deciding factor for me (and it's always the deciding factor) which class can i get the most out of DPS-wise via 1 or 2 button macros. Haven't seen a lot so far and I only got to lvl 15 (which was max for Stress test) so wasn't able to test much there. Eg. I believe Hunters will probably get more dps then a warlock with a simple 1 or 2 castsequence macro? Mages may do better then both. Complete guesses by me though.

My options:
Alliance: Paladin(Healer/driver), Warlock, Mage, Priest, Warrior(Tank)
Horde: Shaman, Hunter, Mage, Priest(Healer/Driver), Warrior(Tank)

IWT worked so well with ISboxer and the Classic Wow client, so I like the idea of a few melee.