I don't know with certainty if HexOS can be fully set up headlessly, I think the answer is no, but could be wrong there. If you can't do it headless, then you would at least need a GPU to do the initial setup; but even a GT 1030 or Arc A310 would get the job done.
Beyond that, I don't think your hardware selection would have any immediate problems but that'll probably depend heavily on what all you have planned for it. I have similar plans to repurpose higher-end desktop parts (R9 5900X, 128 GB RAM, X470 board) for a HexOS build.