I wouldn't go with Tim Thomas. Although I have a great deal of respect for Tim Thomas as a goalie, that man has too much of an ego. I don't think he would be cool with playing a backup role for very long. Sooner or later he'll start speaking his mind and disrupt chemistry in the locker room.
I would probably go with Johan Hedberg. He's always been a solid backup, will assume his role as a backup like a pro, and he should give some solid relief to Lundqvist when called upon.
I dont see how Hedberg is any better the Biron.