I've just finished a re-read of the trilogy and got caught up in mentally casting it all over again:
I also have loose ideas for Hesseth. Possibly Michelle Yeoh or Maggie Q, simply for their grace and elegance. The Prince could be someone like Guy Pearce, who can be gorgeously striking but terrifying. I was going to say Jennifer Connelly for Narilka, but she's too strong a presence already. I'm sure more'll come to me in time :) Thoughts?