Rogue is probably the best with a few fighter levels thrown in.
Wizard leaves you behind the spell casting dept (a full level behind the other characters in the party).
A fighter/rogue is a force to behold, go for two weapons if you like to use the twin sword. We have a human going the same route in our party right now - currently a Ftr4/Rog6 I think and hes a powerhouse.
Be ready to be weak for a while though, your hps will be low, but once you get around level 6-7 you'll come into your own with SR and all.