Re: Safana - if you're a good/neutral-leaning-good MC you've got Imoen. If you're evil/neutral-leaning-evil, perhaps, but why dual her to mage when you can get Edwin, the best mage in the game? That, and as long as you're not going full-on murderhobo baby-eater Imoen will stick with you for a while anyway. Montaron's a passable evil thief, the halfling bonuses he gets are nice. He comes bundled with Xzar who's got an OK specialization but is squishy as hell.
Re: Shar-Teel - you might as well just have Safana if you need a morally-ambiguous thief, or Montaron. Safana's less of a horrid cunt than Shar-Teel, as a bonus.
If you wanted to be weird and evil, you could just get Tiax later, who's not particularly good at either of his jobs but is funny as fuck. Maybe Skie and Eldoth, though Eldoth can be grating at times he has a BALLER special ability.