Not really smart when it comes to these things. I have a Linksys AC1200+ router. I'm wondering what the best modem to get with this is? Cox tested my signal and it was low. Recommended a new modern. Any help would be appreciated.
Not sure about the best modem for you is, but I've had a really easy time with my Motorola Surfboard SB6121. The 6141 and Arris SB6190 models are also very popular here as well.
Check out the list of supported modems as well.
http://www.cox.com/residential/support/internet/article.cox?articleId=b2ec95d0-7ef9-11df-5590-000000000000
I would recommend a minimum 8x4 DOCSIS 3 router.
SB6141 or better equivalent
SB6141, SB6183, SB6190 - Motorolla/Arris
Cm500, CM600 - Netgear
TP-Link has supposedly a good one too, don't remember the model number
