Create a website for online hourly service

I'm seeking someone to create a website (as inexpensively as possible) for a business that performs an online service where time for the service is billed hourly (or fractions of). There will be multiple assistants performing the work/service who will need to log in to the website and track their billable time per client. The website will need to allow clients to create accounts with their information (including service preferences and billing info, paypal). Also, the clients will need to be billed automatically on a weekly basis. There will need to be tracking of which assistant worked on which client's account, so any issues/complaints by a client can be tracked back to the responsible assistant. I will also need a function to review each assistant's hours on a weekly basis and pay them. Thank you