Creating a Patient BackEnd?

I am creating a wordpress site for a local doctor and he wants a portal or backend login section on the site where patients(or people that create accounts) have a section where the admin can send them a message and they can login to the portal to check it, wether like an appointment date or even results to something. Is there a plugin already that creates some kind of portal like that. If not, is there someone out there that could help me to create this functionality. It is a paid job so there is money in it for anyone that can help me accomplish this. Thanks!