I have an idea for a cross platform application. It will require knowledge of several different languages, web development, and system administration/IT. I don't personally code, but I want to pay professionals to do it. I'm wondering how I should go about paying them. Yes, this will be a large project, but I want it done ASAP. Is it ok if I don't pay them by the hour? I really want it to be a set price. Also, is it reasonable to pay them in stock of the company? Like, 20%? P.S. How do I know how big a project will be in order to give the devs themselves an idea?