Start simple and scale up!
You have a great vision with small budget? you have load of content but currently understaffed? You have an eager audience and little time? then start small and scale up.
Web app- why?
Extremally flexible web environment makes it a perfect tool to design the way you want to tell your story. Starting from Editing your text and media independently through choosing interaction element and up to designing your own scene scenario and elements dependencies with your own graphic design. Your digital expertise will evolve while making sure it always works!