Have you looked into Google voice It uses the contact list in your Google Contacts. It also integrates into cell phones (iOS, Android) if you were to get one later.
Google voice allows you to send/receive on a computer. The normal interface is a web interface, but I have standalone software for the Menubar on my mac, I assume there must be a Windows systray equivalent. You can even make calls from your computer, if you install the plugin and have a headset. Even if you don't use the headset, you can even "receive" calls with no phone - they'd leave you voicemail, and then you could listen to the VM from your computer (web interface or standalone app).
If you have Comcast and if you have their VOIP, you can SMS from their web interface as well. But I'd still go with the universality of GV.