Hardware suggestions welcome

This machine, shiningsilence.com, is having some issues.  I had to power down because of unrelated problems, and the system couldn’t find the kernel on the next boot, though the issue disappeared on the next boot.  That’s enough of an excuse to build new…

Any hardware recommendations?  I’m interested in hearing what chipsets/disks/RAID setups/etc. and/or hardware suppliers worked well for people.