Tough question!
I am writing my own scripts lordaron, I also host all my sites on my own servers and run mail and dns servers of my own.
I looked for a ready made script at first, but couldn't find any script that does what i need it to do. Just like i did with the script that powers my LL's
if you are into programming, and can manage sql servers with ease then it shouldn't be a problem for you. just many hours of code writing.
otherwise, you might want to try ready made ones that might be customizable to your own needs.
simply search for portal software in major SE's.
Hope that helps,
Good luck
