[NJARC] WiFI Cable Modem Router question???

[Joe Devonshire via NJARC]

Greetings from Maine,
 
    The latest in our ongoing saga is how to get  electronically connected 
to the outside world.  The provider of choice is  Time Warner Cable.  Oh how 
I long for the days of  Verizon.
 
    Anyway, I'm trying to figure out how to eliminate  TWC's rental 
charges.  One charge I want to eliminate is the Cable, Modem,  Phone Router.  I 
have a WiFI Cable Modem Router.  What I need to  add to this mix is Analog 
Telephone service.  The phone service is included  in the package deal.  
 
   What I am looking for is a VoIP converter for my phone  service.   I can 
use one of the ports on my Router for the  converter.   Has anyone had any 
experience with this type of  service?  Does anyone have any recommendations 
for a  converter?  The TWC equipment is antiquated.  I have a Netgear  N600 
WiFi Cable Modem Router (Model C3700).   I saw a LinkSys  converter that 
might do the job, but I don't want to waste money either.
 
Any thoughts or suggestions?   
Thanks,
 
Joe Devonshire