Range Extender other than the one from cox that works with Cox Panoramic wifi router/modem

I recently had to re-do a new account with Cox Communications.  I was informed about a package that included Cox Panoramic WiFi router/modem.  Since I already had a LInksys router and WiFi extender that works pretty well, I was at first skeptical.  I decided to try the Panoramic WiFi router/modem.  When I got home I set everything up with little trouble.  I reset my Linksys Extender to factory default thinking I would redo the connection with the Panoramic WiFi router/modem.  Silly me the Panoramic router/modem does not recognize the Linksys Extender so there's no pairing of these two devices.  So now the consumer has to RENT the Panoramic WiFi  router/modem and the Extender....I should have known this from the start.  So now I'll take a bold step and ask if there's a range extender OTHER THAN the one from COX that will work with the Panoramic WiFi router/modem?