Sorry man, I am on mobile so I keep missing parts.
As for hardware, I would recycle anything you have at home if it has at least 8gb ram and a network card. Specially laptops (low watts consumption and built-in battery in case of power outage) are my favourites. But if you want to spend for new stuff, the low power N100 are all the rage nowadays.
For storage, go with at least two disks or ssds or nvme in RAID1 (and keep in mind that is not backup, which you should plan to do), they can be external USB drives as well, provided you spend some good money and don't go cheap on the USB enclosure. Mine have been working perfectly for the last decade.