joomla Learning comopnent

we need component to do the following things its for online school site - creat courses depend on categories admin provide - each course must have articles in it that students can read, articles mean classes - teachers can add files to each course so students can download. - students can upload files depending on the course they join - students cant see the course or what it have inside unless they pay for it - if a student join class A he cant see what class B have. - students need to pay to join the class by paypal - admin can configer every things from back end in friendly user way we pay 200 - 300 for this component this component we need instillation file for it as we will sell it to our customer so it have we have alot of work like that if you are intersted in doing component for sales share please let me know .