Min Zife: Greg Itzin
Koll Azernal: Peter MacNicol OR Larry Hagman
I'd say reverse Itzin and MacNicol. Azernal always stuck me as being much tougher, and Zife as being much more timid. MacNicol is able to do that timidity very well while mixing it with a sense of real responsibility, while Itzin can do menace very well.
Though, really, I'd prefer to see Bruce McGill.