Sounds like a fun project. As other commenter stated, those brackets really make the best use of an old case. Can’t think of a better solution for that. For power, you can grab one of those 200w USB power/charger adapters, put it in the case and feed the power cable out the back. Might look a little janky, though.
Good luck! Let’s see what you come up with!
Dude needs to update to the latest Moodle. Looks less like a Geocities inspired html abortion.