Fine, but get John Constantine right this time. British, sarcastic, middle aged. Maybe played by Jason Isaacs.
I'd say James Marsters myself. Maybe not a big enough name though?
I think Zatanna's current look is much more movie-friendly. I hope Del Toro sticks with this project, it ought to be right up his alley.
I like Zee's old costume, and it seems to work pretty well in animation (see Young Justice, for example), but I think you're right on here.
This sounds like a great project and perfect for Del Toro, I hope he sticks with it.