I'm moving a collection of websites I'm hosting for various
individuals over to a Mac OS X based server.  However, I want my
customers to be able to access a basic control panel to make changes
to their site.  I've found many solutions for an e-mail based control
panel, but I'm looking for something overall.  An example of what I'm
looking for is below:

http://www.serverlogistics.com/hosting.php (scroll down to "Custom Control Panel")

Any help in finding such a panel would be appreciated.