@MoonBoots:
There is no universal "perfect" resolution or "bad" resolution. Viewing comfort with 65" and 1080p depends entirely on your own eye sight and viewing distance. It could be that the text is too small, but it might alternatively be too big. You'll just have to see for yourself.
First things first: for HDTVs, there's not that many resolutions to choose from, it's pretty much either 720p (HD Ready), 1080p (Full HD) or 4k (Ultra HD). I'd recommend going with 1080p for now.
IIRC correctly, the recommended viewing distance for work-related stuff is 1.3-1.5x the display device's size in diagonal, with 1x usually stated as the bare minimum. If you get closer than that, you'll have to start physically moving your head around to actually see what's happening on the sides of the display area. For movies, etc. 2-2.5x is recommended. For average, let's take something like 1.8x. For 8ft, that adds up to about a 53" television. Your 65" diagonal size and 8ft viewing distance would amount to 1.5x, so it's still within bounds, but more distance probably wouldn't hurt. If you have ample space to increase the viewing distance, then no worries. But if the 8ft is the maximum distance you can get into, then I'd stay below 55" and adjust the distance to something smaller, if need be. You should maintain breathing room to both directions, as you can't alter your own eye sight nor the diagonal size afterwards, let alone resolution. Distance is basically the key component with which you can adjust the viewing comfort.
Nevertheless, not ALL televisions are good for computer usage. And I'm not talking about input lag here; some sets have unavoidable "features", like edge sharpening, dynamic contrast, etc., which can deteriorate the overall image quality. Some of them might be good for videos, but usually bad for computer stuff. You'll have to read reviews to get more info on how each set is suited for computer usage.
And like someone already said:
HDTVs are indeed more than 99% of the time limited to 50/60Hz input, while the output can be 100/120Hz. Though this might not always guarantee motion interpolation, either. They might advertise "200Hz" HDTVs, which in reality are just 60Hz panels with strobing backlight, without any sort of motion interpolation in place. In any case, your computer will still recognize it as 60Hz HDTV, regardless whether these sort of extra features are enabled or disabled. And thus the computer won't even TRY to send a 100Hz signal to the set.
For example, my own set is advertised as "700Hz", which combines strobing backlight, motion interpolation, and various other settings, some of which have actually nothing to do with hertzes. In reality, it's a 100Hz panel, but still limited to the common 60Hz input signal.
BUT: there are
unofficial methods to "unlock" 100/120Hz even at input level. But this doesn't work with all products.
