gychang,
Let me back up a minute to make sure we are on the same page and to help some other HDTV beginners out there.
HDTV 101:
To get HD, you need 3 things, none of which can be ignored.
a) HD source
b) HD connection
c) HD monitor
a) An HD source is any audio/video source that has HD audio/video information. These include (but not limited to) HD cable set top boxes, Digital Satellite (DirecTV) HD set top boxes, HD DVD, Bluray and upconvert DVD players, computers, etc.
b) Once you have a source, you need to connect it. There are two ways of doing this. One is to use component cables (they are three RCA-type cables, color coded blue, green and red) and an HDMI cable. Component cables carry an analog video signal up to 1080i or 720p but no audio. HDMI uses a small single cable to carry digital video. In addition to carrying a digital video signal, HDMI carries digital audio. HDMI is very common and is quickly becoming the connection of choice. DVI cables carry the exact same video signal as HDMI. DVI is commonly used on digital lcd flat panel monitors for computers. Unlike HDMI, however, DVI does NOT carry audio and has a different connection. HDMI and DVI are both capable of 1080p signals. Note: stay away from big box stores when buying cables. The quality is fine, but the markups are absolutely insane (5-10x is not uncommon).
c) There is simply too much info to try to fit in here. However, in my previous post I stated that size vs. resolution vs. viewing distance is important. A handy article to this can be found here:
http://www.carltonbale.com/2006/11/1080p-does-matter/
I'll be glad to answer any questions (or at least try to) that you post here concerning the display itself.
There is one scenario where you do not need the 3 things listed above. And that lone situation is over-the-air local HD broadcasts. To receive these, all you need is an over-the-air antenna (nothing really special) and a HDTV with a built in HD (ATSC) tuner.
Going back to your original question, I do not have the cox feed. They probably use an HD digital set top box (like the one I use with a different provider). I would contact them just to be sure, and also ask them what the HD connections are on the back of the unit. It will most likely be component and HDMI. Sometimes you can get a cable company to throw in a cable or two, but dont count on it, and cetainly dont expect them to be of good quality. IMHO, if you spend over $1000 on a good AV setup, dont go cheap on cables to lower the quality. Spend the extra $20 and you'll be glad you did.
Good luck with your purchase,
Jau