Unless you have a lot of money to spend NVMe for a NAS is not worth it. To get the most out of the speed they provide you would need to upgrade your network to a 10GB system, and guessing you cant upgrade your NAS card.
A standard 1GB network maxes out at 125MB/s transfer speed.
A Raid 0 will not benefit from an speed increase, it will maximize the storage space but if you lose a drive you loose all your data.
Raid 1 will mirror the drives so if one drive fails you still have your data. But this does not protect against deleted files, virus, or corruption as what happens to 1 drive happens to the other drive at the same time.
I just put in 3 Seagate IronWolf 8TB NAS drives in a raid 5, netting 14.5TB of space. Across a 1GB network i was topping out at around 100-107MB/s backing up a 4.5TB steam folder, in a perfect world 125MB/s would be the max on the network and the drives could sustain 212MB/s which is well over what the network could provide.
On a side note 3 IronWolf 8TB drives cost less then a single Samsung 870 QVO 8TB 2.5" drive