Advise and setup a plugin for members area

You have to advise free/paid plugin (we can buy plugin but will prefer who will advise free plugin) to develop members portal where users can create account and login, admin can upload files and registered members can download it. Members can chat with each/send messages etc. No more fancy things. proposal without starting with FANCY will be deleted straight away. It is a fixed $10 project, Do not bid if you do not agree.