I don't have experience with that board, but my experience in general with 4000 MHz memory is kind of poor (granted we're only talking about a couple kits/boards/processors). Hitting memory speeds that high can be limited by both the board or your processor's IMC, so you run into a lot of potential problems.
In my VR box, I am running TridentZ rated for 4133 19-21-21-41 at 3800 15-16-16-32 and tight sub-timings because either the processor (i7 8700K) or board (Z390 Aorus Pro Wifi) won't boot reliably above that point. I have another 4000 C17-17-17-37 kit and it will run no faster than 3800 either, so it's not the memory that's the problem. On top of that, I actually managed to burn out my previous Z270 board by even trying to run it with 4000 MHz memory. I didn't think that was even possible--maybe the board had some other defect?--but after trying to boot at 4000 MHz memory, the board went into a boot cycle and after powering down and removing the battery the board was dead and would no longer boot at all.
You definitely want to get Samsung B-die, but honestly my advice would be to just get TridentZ 3600 MHz C15
and then try to overclock it. That's what I'd do if I had it to do over again. That's a pretty good bin, it will cost you a bit less money, and either way there's a decent chance you're going to encounter some other limiting factor that prevents you from hitting 4000 MHz stably. Beyond 3600 MHz you're hitting seriously diminishing returns, so the performance of 4000 MHz over 3600 MHz at tighter timings isn't going to be much anyway. In fact, if you have to relax timings a lot to hit higher frequency, performance may actually go down.
Otherwise I guess you need to look at something like TridentZ 4000 or 4133 C17-17-17-37, but that's going to set you back $50 more. If you go 4000/4133 C19 it's still slightly more expensive than the TridentZ 3600 C15 and I'd say it's questionable whether it's actually a better bin. Also with 3600 C15, it will almost certainly boot at XMP settings, whereas that might not be the case with the higher rated memory. If the memory won't boot at rated settings then you end up having to customize all the timings yourself for whatever frequency you settle on (which, granted, you should do anyway, but it's nice if XMP actually boots as a starting point). I definitely wouldn't even waste the money on memory with a higher frequency than around 4133.
Anyway, that's just my two cents.