I think Dushku could do very well as Lady. She is an excellent actress with a great deal of range; you'd need someone who can be both imperious and reluctantly vulnerable, and she has done both well in previous roles. I like Chloe Bennet a lot as an actress, but I haven't seen the same level of acting skill or range of roles from her.
More important than casting, IMO, will be budget, writers, and directors. Is this Game of Thrones level work, or Legend of the Seeker?
In any case, as Richard suggested, I hope it helps Glen Cook in a big way. I'm going to watch it in any case.