Good points, Rob - there is a significant distinction. Most startups need both BD and sales, but typically a founder will handle the partnership development if they're capable.
I'd add just a couple of thoughts. Great media buyers often make good sellers of media, since they understand the lingo and the value proposition. Ex-agency people, for example, with job titles like account manager or account executive (not media planners unless they are outgoing, though - acct mgrs typically have client facing experience). In Atlanta, you can look for people who used to work at Moxie, Performics and 22-Squared, all savvy digital shops. Hit up some local digital marketing events as well, face to face you'll have a sense of people right off the bat - and you can ask around there, where it's typically ok to announce job openings if you're not a recruiter.