I'd use off the shelf consumer hardware. High density Supermicro chassis with SAS uplinks back to a single server. 2+TB consumer low-power disks. Software ra

I'd use off the shelf consumer hardware. High density Supermicro chassis with SAS uplinks back to a single server. 2+TB consumer low-power disks. Software raid (eg. ZFS) to manage it all. And finally, host it a site office or low-grade colocation facility.