UHD

Just need a HDMI 2.0 wire. However you are not going to get 4K from Cox, or any broadcaster, so there is no point in needing anything special for your cable box. Any HDMI capable of 1080p will work fine. See here for more info.

To get 4K, you would need a device capable of it (Roku, Amazon Fire, Blu-ray player, etc) and the service to go along with it. This would have nothing to do with Cox though. See here for more info.

C'mon, Deb202 is an audio/video enthusiast...so she shouldn't get just "any" HDMI cable.

Look for HDMI 2.0a...aka "Full Capability" HDMI 2.0.   HDMI 2.0a passes data at 18 Gb/s...as opposed to the "Partial Capability" of 2.0, witch passes data at 10.2 Gb/s.  This higher data rate will properly handle the advanced color gamut and High Dynamic Range of UHD.  Data, data, data!

Of course, your newly-purchased UHD TV should have the HDMI 2.0a ports, right?  Does it?

Bruce said:
C'mon, Deb202 is an audio/video enthusiast...so she shouldn't get just "any" HDMI cable

HDMI is a digital cable, so generally speaking, most will work as long as they meet the specs. All you need is HDMI 1.4 or above for full 1080p. HDMI 2.0 with "High Speed" is only needed for 4K so would be a waste of money since any cable box maxes at 1080p. However, I would suggest getting HDMI 2.0 to connect your blu-ray or anything capable of 4K.

Stores likes BestBuy are famous for selling you over priced HDMI. Even if you do decide to get a "high speed" HDMI, you shouldn't have to pay more then 10$. Check out this HDMI from Monoprice. Everything you need for under 4$ plus shipping.

Yes, Cox clarified no UHD programming is available, so my comment is for the streaming sources, such as Roku and any forthcoming UHD Blu-ray player.

Deb202 bought a 4K TV and if she does get a 4K streaming source, she'll need a higher bandwidth cable.

When you say "meet the specs," what specs are you referring to?  That's rhetorical because the only specs available are for 2K.  There are no specs (standards) for 4K.  UHD is more than just 4x the pixels.  There has to be a wider color gamut, deeper color bit rate, higher dynamic range, reduced color compression, etc.  These are the ooh's and aah's of Ultra HD.  I don't know how Netflix is producing their 4K content but will it be the same as HBOGo?  There has to be standards and when some alliance does ratify one, you'll need the HDMI 2.0a cable and ports to carry the data.

For now, everything Ultra HD is based on 2K standards.  If you want to future-proof your stuff, look for HDMI 2.0a.

Bruce said:
what specs are you referring to? 

The specs for the given output. 4K vs 8K. 24Hz Vs 30Hz Vs 60Hz etc. Also if Deep Color is needed or ethernet over HDMI. Different devices output even 4K in different ways based on configuration and capability.  For instance, the HDMI I referenced can only do 4K at 24Hz. If OP is going to be streaming higher then that, she would need a different HDMI, but that will work in most cases. 

Bruce said:
There are no specs (standards) for 4K.

That is my point. Since UHD can be either 4K or 8K, and neither are standardized, I was requesting what specs the device she plans to use will use.

Bruce said:
If you want to future-proof your stuff, look for HDMI 2.0a.

I agree. However HDMI 2.0 still vary greatly. HDMI 2.0 vs 2.0a,  build quality, etc. To be honest, it isn't even certian HDMI will stay the standard. With Displayport, USB C, and now the new MHL taking off, I predict HDMI will start to lose it's market hold. I am hoping USB C becomes the norm. Is HDMI the only option on the UHD TV? What model TV?

NERD COMBAT!!! 
 

You said HDMI 2.0 with "High Speed" is only needed for 4K.  Meh...it won't even support HDR metadata extensions.

Bruce said:
Meh...it won't even support HDR metadata extensions.

Not saying anything you are saying is wrong. Just think it might be outside the scope of what OP was asking. Then again, I think we both scared her off. 

Whoever duped her into buying a UHD TV should have scared her.