lokibear,
As you know GV does not provide 911 service. Many (most) VoIP providers do offer the service although its my opinion that the phone company's 911 service is without equal. The phone company also provides power so that their lines work during a power failure so long as your telephone handset does not depend on your house power.
It is possible to have an OBi110 attached to your Qwest(CenturyLink) phone, GV, and another voip provider that allows you to bring your own device. You can setup the 911 service on the 2d voip provider.
I would start that way with GoogleVoice and an additional VoIP pay-as-you-go provider like Callcentric or
voip.ms setup for 911 and occasional outbound calls. There are also other good pay-go providers. Add one of their cheaper incoming numbers (DID) and get all that working and port your Qwest number to them when you are ready. Both CallCentric and
voip.ms have an option to show your current Qwest number as the outgoing caller id for calls made thru their service. If you like you can setup one of them for both incoming and outgoing calls, the other for outgoing calls only. Of course this is in addition to GoogleVoice.
I would initially get an indication from your selected voip provider that it is possible for them to port your number. Some Qwest locations are rural and you might run into a problem.
With GV the outgoing caller id will be your GV number but the advantage is the calls are without cost at least thru 2012. Of course you might decide to adopt the GV number as your primary number and drop using your other number.
If there are additional voip provider(s) you wish to setup for occasional domestic or international calls you can add additional outgoing only providers.
I would attach your cordless phones to the OBi and they will be able to receive incoming calls from your PSTN line and your voip line(s). After you port the number and drop your PSTN line service and detach the phone cabling from the utility company lines you can cable the OBi to that house wiring.