Actually, WAR/WHM is fine. There's several pieces of MP gear you can use, and you have refresh drinks as an option also. I once leveled as a RDM/WAR tanking to low 30s on retail because until around level 30, RDM could wear pretty much the same armor that WAR and PLD could. At low levels, it's seriously not much different from an actual PLD. You're not going to want to take that much higher than 30 though.

I leveled MNK to 75 as a tank too (no I don't multibox). Tanking isn't really that big of a deal. I've tanked parties on all different kinds of melees with no PL.