Good news and thank you.
The recommended debian-edu-amd64-i386-NETINST-1.iso worked on the VirtualBox without any hiccups. Now I can burn it on a CD and try it on real hardware.
The revised "dd if=" method worked on the debian-edu-amd64-i386-NETINST-1.iso, starting up on my laptop. (I didn't complete the install, since I got a working system there).
Now I can now return optimistically to the school and retry the server installation :)