I agree that Russell as Carth, Kate Beckinsale as Bastila, and Oldman as Malak are unquestionable.
As for Revan, it's a bit hard to say. I agree that either Christian Bale or Guy Pearce would be really successful in the role, but what about Matt Damon? For some reason I could really see him in this role.
I know i'm going to get criticized for this because Samuel L. played Mace Windu, but seriously he's perfect for Jolee.
And Ray Park as Darth Bandon. Just cuz Bandon has barely any lines and Ray Park needs a job.