I personally had the best experience with mergerfs (Drives can be any size and can be backuped by snapraid) and an external enclosure up until recently. Unfortunately USB is such a limiting factor because of bandwidth and also latency. I can only realy recommend to get a new cheap Server which has Support for sata If you want any usability while Transferring or moving files.
I think his biggest problem is package installation for which he can use discover or his equivalent for his de.