Considering the breadth of the tasks you want accomplished, you might want to look at different distros for different purposes.
For instance, I like Slackware for running servers that I don't need to run X on, such as webservers or networking boxes. Slackware isn't pretty, but it's streamline and configuration files aren't generated messes. It's nice from a sysadmin point of view.
For desktops/fileservers, I tend to stick with RH. While it's not necessarily the friendliest distro, it's got the most support behind it. If you're going to come out with a program, you're going to support RH 99% of the time.
Why fileservers? Because my experiences with RAID is that drivers tend to be proprietary, and at least in the case of Promise tend to release only for RH.
Finally, if you want to keep you're current RH servers, but want up2date past EOL, check out
Progeny. They'll provide your patches.