Looking specifically for a paid for service. Not sure if the dragon you are talking about is part of Dragon Naturally Speaking which I am not very thrilled about.
Has anyone tried grasshopper?
Obi has a list of other providers on their site.
Use TWilio and you can route the calls to your cell phone or obi device.
You can also have an ext tree, office greeting etc...
Number are $1-3 per month plus 1.5 - 3 cents per minute. If you need help setting it up let me know.