So, the first Monoprice extender linked will not work because in the specifications it is only rated to 10.2Gb/s, which is too slow for HDR 4K content. This is something to watch out for as it is a VERY common thing to specify 4K and even 4K/60, but still be at 10.2Gb/s when HDR 4K requires 18Gb/s.
The next two cables you linked to are both rated appropriately as 18Gb/s HDMI cables. We are seeing it more and more that 18Gb/s cables are fully rated to that specification. You can be assured that with those cables that they will carry the full bandwidth that HDMI 2.0 offers.
Now, the ENTIRE context goes back to the second response you got from
@highfigh - RUN CONDUIT!
RUN CONDUIT! RUN CONDUIT! RUN CONDUIT!!!!
HDMI 2.0 didn't exist a few years ago. HDMI didn't exist 15 (or so) years ago. HDMI will eventually be gone, and if not, the 18GB/s HDMI cable will definitely be replaced by a 49Gb/s HDMI cable. (8K)
RUN CONDUIT!
Carlon 1.25" conduit is the appropriate size to run with sweeping bends in it to allow smooth pulling of a HDMI cable. You don't have to run the current HDMI cable through it, but you want that conduit in place as it is the only true way to 'futureproof' your system.
With a 50' run behind walls, there is ZERO question that conduit is the most important thing you can do from the start.
Well, unless you have a good way to add/remove cables after the fact which is sometimes possible in certain setup situations. I've been in homes where I was able to pull HDMI from a rack to a projector without creating new holes... But the situation to do this is often quite rare.