Hallo Johan, no need to go with an guided, organised tour. It will cost you an arm and a leg, you can do it much cheaper when you make your own arrangements. Use a travel agent to book your flights, they can also help you with advise how to get from the airport to your starting point (train or bus).
Once you are on the trail, you can make your own bookings for accommodation. You can also use booking.com. I did the Le Puy en Velay route in France in Sept last year and had no problem with accommodation.