We want to offer FTP to our customers.
We are an online backup provider, so FTP will be our simplest product.
We have a WHMCS installation.
We need an FTP server software recommendation and installation (Windows or Linux) which provides the usual features such as SFTP, zoned home folders, quotas etc.
The system needs to snap into WHMCS for account creation, billing, suspension and reporting on storage and bandwidth etc. It will need to support multiple FTP servers.
We are happy to use a ready-made product or work with a WHMCS expert who can build on top of an open source FTP server.