Hello,
Here you will find a list of compatible modems (The link might not work):
http://support.cox.com/sdccommon/asp/contentredirect.aspAmbit
60678EU
U10C018
Cisco
DPC3000
D-Link
DCM-202
Joohong
SL2810
Linksys
BEFCMU10 v3
BEFCMU10 v4
WCG200
WCG200 v2
CM100
Motorola
SB5100
SB5101
SB5120
SBG900
SB6120
RCA
DCM315R
DCM425
Scientific Atlanta
DPX2100
DPC2100
SMC
SMC8004
SMC8013
Terayon
TJ715
TJ715x
Toshiba
PCX2600
Zoom
5241
This is my reccomendation based on ease of installation, performance, and longevity:
I hate to say this but 90% of the listed modems are discontinued! There are VERY little all in one cable modems sold any more. You might get better luck buying a modem and wireless router seperate.
Secondly, call COX to get a suggestion of modems. I would suggest purchasing the modem from cox, as they really dont mark them up that much if any, and they push firmware updates down to their modems regularly. Its best if they can maintain the modem.
Then pick up a linksys WRT54G or something of the like. I really do like linksys in this department.
Good Luck!