They've pretty much covered it.
You've knocked out most of the alternatives, by the way. You don't want to be a rogue, tank, arcanist, or nature type. You've really only left archer, monk and cleric.
Maybe you should shoot for Shadowbane Stalker (Complete Adventurer). It's a pretty non-traditional rogue build (and probably not cleric enough to trample on your other cleric, but enough to chip in). You could build it either as a paladin/rogue or a cleric/rogue.
Requirements are light and can be met at 5th level, letting you get an early start on the pclass. It's not a real power class (you won't have full spellcasting), if that's a concern, but it doesn't utterly suck either.