Which, IMHO, is asking for trouble. Having something for non-IT nerds can be hard, but is definitely not impossible, but trying to do it headless is just a level of complexity that's not at all necessary. The non-IT nerds are going to be significantly less able/willing to trouble shoot that mess if it ever breaks, especially given how many ways systems can break that would disrupt some combination of VNC, SSH or the net stack in general.
If it were me, I'd use partition management software that can send data over the network and either a live USB drive or virtual machine to interact with it. Or just copy what Raspberry Pi does, except set it up to automatically write to blank disks. But, whatever you do, there's going to be an unnecessarily high risk of various bad things happening.