Necromancer is probably the FASTEST levelling character type (solo or duo)Albion has to offer - its a pretty deadly PvE class, though lacking in power for RvR.
Armsman, Heretic, Reaver, Mercenary are all good damage absorption and function very well as the tank of the group.
Friar, Cleric, Minstrel, or another Heretic would do well with any of the above characters.
Scout/Infil combo would do very well in RvR, but lacking healing or the ability to stop any adds you may get, coupled with the fact that you dont have the ability to taunt or any heavy armor between you to absorb damage (granted you do have evade) - will definately slow you down.