I am gathering that you wish to use your existing Internet connectivity from each location as the vehicle for interconnecting the network. If that is the case then yes. a VPN solution is likely to be your preferred option.
However, if you are not adverse to the expense of adding point-to-point lines between the locations, that would be a "better" option, primarily because you can commit the bandwidth needed to interconnect the various LANs into one network, where if you use the Internet, you are subject to the vageries of using the Internet as a transport.
If you have had solid connectivity to the Internet from your various locations, it would definately be less expensive to implement a VPN solution.
Good Luck
