For a tiny FullPliant server computer, you need a PC with:

Using 2 IDE disks, and an UPS, is very much recommended in order to provide RAID 1, even on a tiny server.

If you have only 1 IDE disk, using an IDE engraver for backups (connected on the second IDE channel) is a very good idea, but if you have 2 IDE disks in order to provide RAID 1, then the IDE engraver will not be reliable, so you need an SCSI CD engraver.