I thin the main thing I'm needing to know is how to get PHP to work in sites created by ISPConfig. Reinstalling the OS is a definite possibility, so let's not rule that out. I can move the existing sites to another server in the interim, then after reinstalling the OS and ISPConfig and creating sites, move them to their new homes.
I'm not serving "hundreds of sites" just a handfull (less than twenty). It seems like ISPConfig should be able to handle that easily.
With that in mind, if I install ISPConfig on a freshly installed system and create sites with PHP enabled, will ISPConfig support PHP on those sites?
If I do that, I'll use Fedora Core 4 and wll follow the Perfect Server setup.