If you're willing to hire a full time person, Google's AdWords team has hundreds of very talented optimizers and account specialists who are in general fairly unhappy with their jobs. They have very deep knowledge of PPC/Adwords from the inside, and have seen a variety of client accounts.
Google doesn't do a good job of nurturing since they tend to hire highly intelligent nontechnical people, train them all about Adwords, but then give them no real way to move up in the organization or challenge themselves.
Google doesn't do a good job of nurturing since they tend to hire highly intelligent nontechnical people, train them all about Adwords, but then give them no real way to move up in the organization or challenge themselves.