How to build comprehensive database of conference companies, events, and contacts?

On behalf of a friend, does anyone have ideas on the query below?

“I am launching an internal speaker’s bureau for a professional services firm. My role is to win speaking engagements (both unpaid and paid) for the senior executives at my firm, particularly in financial services. I would like to compile a comprehensive database of the major conferences worldwide and the speaker selection team at these conferences. My question is: What is the best way to track these events and the speaker selection team information? Should I use an open event platform such as www.Upcoming.org ? Does anyone have any other advice for me? I’m particularly interested in talking with people who work at major speaker bureaus, who could give me insight on these questions. I’ll share my results with Speakernetnews, in the compilations section: http://speakernetnews.com/post/index.html .

Please post your suggestions in the comments below or in a trackback. Thanks!