I have already implemented large applications that do much the same thing you should do your project, I work very well with boostrap, but I've never worked as a freelancer, always in companies developing software, which you can bring to your project unlike others, is that in addition to the technologies required for the project can use other that will allow your application to be even faster because you will be working with videos and now with high definition videos become very heavy and can cause the application is slower, if I get the chance I'm going to reduce as far as possible that can cause slowness large files in your application