I would stick with a purebred yorkie. You really don't know what your dog will look like if you get a mix - it could look more like a yorkie or more like a poodle. If you want a yorkie, then get a yorkie... just my opinion.
As far as their coats go, an adult yorkie should have a straight, silky coat. They do not generally stay curly once the puppy coat grows out.
Good luck with your new puppy! You must be so excited
