linux hosting apps

Hello,
     Here is what I wanna do and hopefully one of you people can help me.
Most of our web hosting is centered around our Winblows based e-commerce
package and thus those sites are stuck with IIS.  However, we do host a fair
amount of generally static, non-commerce oriented sites. Now, what I want to
do is move them to a linux based server and offer them self service tools
that give them greater control of their account.  For example.  I want to
set up a tool called PHP webhosting that is similar to geocities in that it
has a nice web interface for managing site content.  Also, I plan to run
Qmail with qmailadmin on vpopmail and allow the owners of these sites to
administer their own e-mail.
     MY QUESTION IS, is there other web hosting software out there for linux
that will allow me to add more value and self service to those who host on
our mighty linux web server?  I appreciate the time you took to read this
message and apologize if my question was not stated clearly.