Artificer.

-can handle traps/locked things, aside from safety issue trap bonus and perception bonuses self-available.
-good dps.
-self-healable, either with wands/scrolls if fleshy or own spells if wf.
- Force damage line enhancements plus blade barriers equals good things at higher levels.
- can solo that irritating four man quest in necro one for the silver flame favor with a regular hireling, dog, and one gold seal hireling.
- Is not overly gear intensive.

This is just my suggestion, there are a lot of solo builds in multiple classes around.