The new box is an Alphaserver 4000 5/400, with two CPUs and a gigabyte of RAM. It, too, will have a RAID array, this time with all new drives and controller. It's run flawlessly so far. I've got Gentoo Linux installed on it, and current versions of all of the software in use have been installed and configured. It'll be overkill for the use it'll get, but I want as trouble-free a system as I can get, and this seems to fit the bill.
I'm going to run it over the weekend just to see if it craps out. If not, I'll move the user files over to it Monday afternoon and make it the running server, and then all of the outages and so on will be behind me - I hope.