For anyone who may find this thread in the future… some of those old Compaq servers are a real pain to get any BSD or Linux distro running on. I have some Compaq servers of that same era and tried pfSense, stock BSDs, several Linux distros and none would boot regardless of BIOS settings, having all the latest firmware and BIOS revision, etc. They run Windows 2000 and 2003 no problem.
Sometimes your best bet is to do as Gob did and find a different piece of hardware.