What TV and brand with HDMI and settings for 4k and 8K quality to use consoles (xbox one x,...

I would use the HDMI cable that came with the Xbox One,

Third Party cables can be hit or miss depending on there quality,

I connected my X-Box One first generation to the HDMI 1 port using a brand new cable compatible with
HDMI 2.0 and 8K resolution.

8K over HDMI 2.0 is not possible, A cable that can run 8K needs to be HDMI 2.1,

also the OG Xbox One uses HDMI 1.4, both the One S and One X use HDMI 2.0

I believe that, with your Xbox one being HDMI 1.4 it's not forward compatible with your TV HDMI 2.0 ports as to possibly why your low latency mode is grayed out, or it just could be the third party cable your using, best to try out the cable that came with
the Xbox.

Error when selecting the 4K UHD resolution on Xbox One X and Xbox One S

You receive the following error message when you choose 4K UHD in display settings:

That didn't work

4K is supported by your TV, but not at 60Hz. You won't be able to upscale to 4K, but, depending on your TV, you may still be able to play some 4K and HDR content. To see what your TV supports, choose 4K TV details.

This error occurs when the console detects that your TV supports 4K, but doesn't support a 60 Hz refresh rate. You may still be able to play 4K content at other refresh rates, but you won't be able to upscale the system, games, and apps to 4K.

Solution

To determine what your TV is telling the console about its 4K capabilities, see

Checking your TV's 4K and HDR capabilities on Xbox One X and Xbox One S. Use the 4K TV details screen to see what changes as you try different things:

• Make sure your HDMI cable is plugged into the correct port on your TV. Some 4K TVs only support their full set of 4K features on specific HDMI ports. See your TV manual to determine if there are special 4K HDMI ports, or try different ports on your TV.
• Check your TV's settings menu. Your TV might have a special mode that controls your TV's refresh rates. See your TV manual to determine if you need to change your TV's settings.
• Make sure you're using the HDMI cable that was included with the Xbox One X and Xbox One S.
  
• Try a different HDMI cable. Your cables must be HDMI High Speed or HDMI Premium certified.
• Plug your TV straight into your console with the HDMI cable that was included with the Xbox One X and Xbox One S. Some AV receivers or other video equipment may not correctly pass the signal to your TV or console. Also, you'll need to use HDMI High Speed
  or HDMI Premium certified cables between both the console and receiver, and the receiver and TV.

Unfortunately, some TVs don't support 4K at 60Hz. See your TV manual to make sure.

Related Issues
Checking your TV's 4K and HDR capabilities on Xbox One X and Xbox One S

4K on Xbox One X and Xbox One S technical requirements

You have several setups.

This because the console, like was said above will support up to 8K with 120hz - this means that the
maximum performance, is up to the developers to use all that power, some will some wont. You gonna see some games supporting
8k/60hz, others 8k/100hz or 8k/120hz, or the ones that cant or wont use all the power will use like
4k/60hz or 4k/100hz or 4k/120hz.

I know like you said a 8k or 4k/120hz monitors or even TV's are a lot expensive for now, and if you cannot wait for the launch, for a xbox one X you should look for a 4k/60hz monitor, and if you can spend more try look for more hz. But yes for the series X
you will spend more money in a monitor or TV.

why you usent a hdmi extender ? im guessn you have your console no were near your tv other wise you wouldnt be useing one inlee you mean you have a hdmi splitter wich has 2 hdmi for a console and ur set top box or cable n u then plug other end into tv
as the orignal xbox cable hdmo suports 4k hmm if you mean you have two tvs and you are useing this extender all if you mean you have only one hdmi socket on ur tv or two an extender will lose 4k quality only way around it sadly is keep you xbox x plugged
into main hdmi socket and use other devices in the extender

Hello!

For 4K TVs, I think 120 hz with 2.0 hdmi is the maximum that the system will request. Now, for 8K TVs, 144hz with hdmi 2.1 it is necessary. So do not worry.

Hdmi 2.0 can only support 4K at 60hz or 1440p ( 2K ) at 120hz, Hdmi 2.1 will allow 4K at 120hz.

I'm also hoping that the console has a Displayport 1.4, for 4K at 120hz to use on 4K 144hz monitors