Add a voice modem to a CAX80 modem/router?

[pbABQ]

Pre-purchase question:  Trying to figure out how to add voice to a CAX80 setup without going to ooma.  Is there any way to link a voice modem like the CM500V with a CAX80 to add voice capability , but still maintain the speed/bandwidth of the CAX80?  Need the range and the CAX80 looks like a terrific modem/router.  Best way to add voice?

[plemans]

Do you already have the CAX80? 

If so, there isn't much to do besides going with something like the voip (ooma) route. 

IF you don't, then I'd go the cm2050v (if its compatible) and then just a strict router. The RAX80 is the router only version