I'm not sure what scale your looking for, or do you plan to purchase or run your own VPN. I have seen may guides to using the following devices: Raspberry Pi U

I'm not sure what scale your looking for, or do you plan to purchase or run your own VPN. I have seen may guides to using the following devices: Raspberry Pi Ubiquiti Edge RouterX PFsense SG1000 Tiny Hardware Firewall Those are just off the top of my head. We also have some larger commercial units to extend our network across public networks to put remote sites on our network.