Would you have any recommendations on hardware?
Yup!
No matter what external storage you buy be it an external drive / NAS / SAN / whatever, make sure you buy a UPS firstly. I dunno about where you live, but here the amount of "brownouts" through the night damages electronic gear irrevocably and I learnt my lesson.
Best investment(s) ever.
I started with a small APC UPS which most protect drives/devices from anything from a brownout to full power cut for you to power down those devices.
I protect my NAS / router / modem which the former has a USB port that can connect to the UPS via a data port and allows it to monitor the battery level and, if it sees it getting to a
X
low power level emails me and then shuts it down gracefully. Awesome thingys and there's other ways of monitoring themhttps://pimylifeup.com/raspberry-pi-nut-server/
Have fun emptying your wallet ;)