DSD 256/512

I'm not sure if it's proper place… I'm searching for example DSD256/512, or internet shop which sells music in such formats.

I failed to see the point of listening DSD if your software and hardware still works internally using PCM. A full DSD solution is so overpriced that it's main target audience is audiophiles without too much EE knowledge and are willing to pay for snake-oils. Well, if you already have the hardware, just ignore my comment.

That picture is a bit silly. Sure, you'll get more accurate 3 microsecond clicks with a format that has such a massive sampling rate, but that doesn't make sense in a real-world situation. DSD is 1-bit, this leads to high distortion which has to be compensated for. Also, software hardly seems to exist for manipulating DSD (mixing/mastering for example), because being 1-bit makes it too difficult. If you find music in DSD-format, it was likely recorded as PCM anyway, then converted afterwards. I'd say this format is obsolete, mainly because it's 1-bit. You need very specific tools to record it, manipulate it and listen to it, very impractical, limiting and expensive (both for the producer and the listener). Even then, your ear can't tell the difference from 24-bit, high samplerate PCM. It seems cool from a technical point of view, I don't want to sound too rejective, but it definitely has no practical use.

I did find this one though if you really want to delve into it: https://www.nativedsd.com/