If you need a powerful NAS, I highly recommend Synology. I have their 1815+ NAS, and it’s one of the most feature-packed small business NAS devices I could find. Their support is fantastic as well.
I recommend you use Glacier and backup to Amazon’s cloud. You could also use Microsoft’s Azure, but you need to have a Microsoft server presence and configure Windows backup, which I recommend if you have the money. Otherwise, Glacier has a Synology app that will do your backups for you, and Amazon’s backup is dirt cheap.
I also use Synology, and love it. However, I never use the cloud for any data backup. That being said, if you want high availability of data, the cloud would be the answer. I can access my NAS/server in my basement from anywhere in the world. Have done so many times, using the local Wi-Fi access or cellphone hotspot for remote desktop or direct access. Routinely backup the NAS to a separate 8T drive.