Its not going to be easy to retain Frostbrand and Defender for your fighter/druid, as Malchior Harpell's going to be hounding your party. Unless you don't mind putting up with his nonsense, and avoiding him repeatedly, I'd advise taking up other types of weapons. Besides, there are a number of pretty unique weapons lying around. As nephtu said, try for a long two handed weapon. Since your fighter/druid is likely to be a support fighter, get a spear or halberd and poke away from BEHIND the two main fighters, as the long weapons can hit from some distance away. Furthermore having the fighter/druid close also allows for convenient healing and buffing (if required).
For the mage weapon I'd suggest Staff of the Magi. Understandably it's an overused weapon, but since a mage won't be participating in combat, getting a combat oriented weapon really isn't very useful. If it comes down to the point when my mage has to go hand-to-hand, then its time to load a savegame, IMHO.
Just a little joke: Your main char's wielding celestial furry. Is that Boo?
