Considering the easy access to HS internet I would recommend a hosted VoIP solution such as Spectrum or other local provider.  This reduces management issues, has lowest cost to start up, and provides the most features for lowest cost. You might consider working with a smaller company who resells someone else's service - smaller companies will give you more personalized attention and be more responsive to your needs. The technology is pretty much a commodity - provided by a wide range of companies. Personally, I don't mind paying a little more if I get the attention and service I need to keep my company running. Don't scrimp on communications - keep your customers loyal with good communications.