If you're looking to hire a professional editor, I highly recommend Michelle Demers, who edited my first two books. Aside from editing, she also offers other publishing services such as ebook formatting, print layout, and self-publishing consultation. You can view her testimonials here.
For professional cover design, I highly recommend Jenny Q over at historicaleditorial.com. (Testimonials can be found on the same page.) She specializes in historical fiction, but as you can see from the two covers below, she is highly adept at other genres as well.