Virtual Hosting

We are in the process of converting our websites to our own servers instead
of virtual hosting for our sites. My question is about how to get it setup
to work like the virtual servers in terms of ftp and system users. I would
much rather do this than something like NFS and in case we ever do offer
virtual hosting, I want it to be accessible in the same way as any other
virtual server.

Thanks,
John Albee