Recently I've been reading and learning quite a lot about scrum and I like it a lot. However, I do have a couple of likely scenarios in my head to which I don't know the solution. So let's say that I might want to organize an agile team of (for instance) four web developers (one of them UI/UX designer). This team would operate on scrum principles.

Initially we would probably be working on projects like landing pages for ordinary people's small businesses, like renting apartments, selling cookies... Such customers simply can't be set with Product Owner role (IMHO), because they usually expect to hire a company, give them the overall project goal with some details, and then expect the job to be done (including a lot of decision making) with as little of their involvement as possible (in their opinion, they have more important things to do). Let's say I'd like to engage myself in a developer/scrum master role (I know that even that is debatable, being a team member and scrum master at once), so I simply shouldn't take the role of the product owner as well.

So as for my questions: If I'm my company's business owner, do I simply need to be a product owner as well (do these roles include each other)? Can I employ a sales person which might have the product owner role? Would it be better if it is an experienced developer instead of a sales person? Is this even a smart move? Lastly, is there another agile approach that might better suit my position?

EDIT: Thank you everyone for good inputs. I added some comments, any aditional info will be greatly appreciated.