The computer that is thebrain.conmicro.cx serves as the externally visible system for web service, mail, and other functions. Right now, it's a DEC Alpha PC164/500. I've just acquired two Alphaserver 1000A systems, and one, with hardware RAID and the faster processor of the two, will become the new thebrain once I've got it set up. The current system runs Red Hat 6.2, and has for years. I want something much more up-to-date this time. Unfortunately, most distributions have dropped support for the Alpha. One that hasn't is Gentoo Linux, so that's what I'm looking at the hardest at the moment.
When I'm done, the system will have at least twice as much disk space with hardware redundancy. It's got 7 4 GB drives (and I've got 14 spares ready to stuff in it, less whatever I use in the second box), and I'm currently debating how to set that up. The CPU will be slower (333 vs. 500 MHz), but what that system does is not processor-bound anyway, so I'm not concerned. I do plan to add more RAM than the 128 MB that's currently in it.
This will not be a fast process, but when it's done, I'll have a true server-class box that should withstand just about any failure you can name.