Gyllenhaal would interest me the most out of the names you listed if they ABSOLUTELY positively without a doubt HAVE to get a "name".
Phoenix, Malek, Gosling, and Dafoe, as played out as that third choice feels although I love the guy to pieces, would all be fine.
I like Driver better for someone like Scarecrow or Mad Monk as you mentioned once or twice. I only see DiCaprio as a riff on Nicholson's Joker and even then I have no real desire to see him in the role.
Please don't be Depp. Please. I have too much excitement riding on this for it to just be Depp.