Will they have all the skills necessary?

SEO isn’t just about throwing keywords on a page and monitoring the search engines. A good SEO needs to be able to be a decent copywriter, excellent keyword researcher, decent link builder and have a basic grasp of social media marketing and usability. While each of these areas requires a very specific skill set a decent SEO should be well versed enough to be passable in most of the areas necessary to succeed. If more expertise is needed then you’ll have to answer the next question.