Proper Way File Storage

So, I’m looking to see what the best way to setup is.

I have 3 Dell Poweredge R710 with 6x 2TB Hard Drives.
(Ignore 2 of them for now, they are powered off)
I have an HP Proliant 370? I think. Not sure of the model, but it has 4x 240GB SSDs. This server is my XCP-NG host. Just holds, maybe 3 VMs.

My question is, the Poweredge R710 is going to be my storage. Running TruNAS. Should it just be mapped file storage or block storage (iSCSI)? If block storage, should it be setup to a VM/Server directly as a hard drive?

Here is my predicament. I have about 3.2TB of data in a similar structure of (Clients, Company Files, and Home Records/Private). I want to be able to back up to another server or two I have colocated in other data centers for geo-redundancy. Some people ask why I don’t go to the cloud for storage. Have you seen how expensive 2+ terabytes is to host with Azure/AWS? F*** that noise. ***FYI, its over $1000 a month. Over 600GB of data is actively used every week, mainly customer data as we add, edit, move, or remove customers information. On top of this, its all encrypted.

I prefer my VM’s to run over NFS instead of iSCSI

How would you normally do that? Do you have a video on this?

Yes, done with FreeNAS but works the same with TrueNAS