Hey there Dan
You'll probably find that it isn't a case of one or the other. Perhaps you'll end up being an instructor for a few years in order to gain some flight hours necessary to apply for an airline job. On the way to your airline job you might fall into banner towing work or air taxi.
You might love being an instructor so much that you can't entertain the idea of the airline way of life. When I first started out I did just as you're doing. I had it all mapped out. Well things change and 6 years later I'm not a Pilot flying for heavylift as I had hoped! Instead I have had lots of small jobs in aviation (flight planning, ops and tug Piloting) as well as all sorts of other jobs to pay flor flying such as HGV driving and working for a law firm. My aspirations have changed in accordance with what I have learnt along the way.
You can get your head spinning worrying about career paths. Far better to concentrate on getting the licences first and let everything happen as it does whilst keeping a gentle eye on where you are heading in life.
Bill