Which VPN Is Best for Geolocation Testing?

Since I'm working on a project which involves geolocation and suggesting people different pages based on their country, and need to find a VPN or other system which can spoof those as a location.

Problem is, it has to be one with an absolute ton of server locations, since the country choices include everything from the US and Europe to China and the United Arab Emirates.

So is there a good service for this? Perhaps even one which can be used to spoof any country, in the same way Browserstack can spoof any browser/operating system combo? Or will this require quite a few different services to test?