I've been thinking about this too and I think I've arrived at the same products. Heatkiller stuff always looks really good.
It looks like the mounting for the chipset fans on X570 are standard (at least for the boards I've looked at) so that block should work, I think.
Having said that, I may instead just buy an X470 board, live without PCIe gen 4 and avoid the hassle and extra expense of having to remove the squeely fan...