as a business I assume that you will need at least 3 lines (plus fax)
I DO NOT recommend putting ALL of your lines on VoIP...
while you can save money by having some of your lines on VoIP, if you rely on it completely, you are relying on a SINGLE POINT OF FAILURE.... if you lose your cable/modem or DSL line then all the VoIP lines go down as well...
If you are able to mask this as residential, then do so, because most of the time they will cost more for business..
I recommend getting 2 voice lines from a CLEC, (they are a reseller of verizons lines or whoever owns the lines in your area) a CLEC can usuallay get you a cheaper rate then Verizon, or whoever owns the lines in your area..
the other 2 voice (or fax) lines should be VoIP.. your cable company may give you a package deal, but vonage, packet 8, sunrocket, and other voip companies have lower cost packages then what your cable co will offer
compare the price with DSL and cable, DSL may be cheaper, but it is slower, and also, DSL promo offers are usuallay only 3 months, cable modem promo offers (if any) usuallay are 12 months..
you can pick up quite alot of channels with a QAM tuner (built into most HDTVs) while technically "theft of service" if you go with a cable modem, and the tech doesn't put on a video filter, you will have free TV.. they really can not do anything to you, because they are the ones who failed to secure there network or signal from entering into your home or business.. (all they can really do is put the video trap on the line) since you dont want your video to go out one day.. you can get a basic package..
ok.. recommendations :
2 CLEC phone lines aprox $65
2 VoIP phone lines aprox $40
DSL aprox $20
basic cable aprox $20
estimated monthly charges... $145
(damn thats cheaper then my triple play package.. but then again i have OOL boost (add $10) and every channel on my TV, plus DVR...)