Web-based learning management system

We are interested in developing a user-friendly Web-based learning management system. Users should be able to log into the system, create a course, and publish their course for use on- or offline. Courses will consist of static pages with text and graphics, pages with quiz questions, and/or pages with multimedia display (e.g., YouTube video). Users should be able to order these pages in any way that they like. Users should be able to see a progress bar, whether they chose the right or wrong answer for a quiz question, and their final grade upon course completion. Users should also be able to print a certification of completion (.pdf) upon course completion. Users should also be able to customize the courses they create with their own graphics (e.g., logo) and colors. Users should be able to generate reports of student activity (eg, how many students passed vs. failed). Users should be able to create courses for free but must pay (e.g., via PayPal) to actually publish their course. Would prefer to work with a vendor with experience developing e-learning applications.