Hello,
i use three intel nucs as a 2 node vsan cluster.
One of them is the management esxi for DNS, vCenter and Witness, the another one for the 2 node vSAN Cluster.
However you should be careful, some intel nucs has only one hard disk. That's why I have to leave the case open
But you can use 1 or more intel nucs with a qnap as shared storage.