Can anyone recommend a “yellow pages” type plugin, which not only has a directory type of structure, but also has ads which you can insert in to WP sites?
ex: ads rotated randomly throughout the site - the plugin just grabs a random ad and displays it.
It sounds like you’re going to have to hire a developer to build that plugin, or build it yourself. Generally speaking, plugins are created with broad uses in mind - so you might even find a few great plugins, but they might not do exactly what you need.
Head over to Freelancer.com or Guru.com or another one of the freelancing websites and hire someone - your app will probably cost $50 bucks at most.