2 Locations Sync

Hello, I have two locations that basically need to have a local copy of files synced. They are in two cities. Basically, we want to have each location to be able to map a network drive locally instead of using a vpn and when I new file is put on the server it syncs to both servers. I am looking for recommendations of what would work best for this.

We are looking to have 10TB of disk space on this server. Looking for NAS or best scenario. Thanks!

Not sure how this is related to ownCloud. Did you think about making this scenario happen with ownCloud? Where do you have difficulties?