Pretty different, actually. In fact, podiatrists and ear/nose/throat practices, plumbers and trim carpenters may need different templates.
We found that when we began talking to local citizens advocacy groups. We initially thought that they could use the same architecture/structure we use for political campaigns (they're campaigns too, right?), but found out they need a different site template.
Why not just allow the user to select his business type, and offer a default template of content and items -- and they can customize it some more.