I got this problem with the very latest antergos-minimal-18.5.
I tried this several times with the minimal and full iso and once got it to run when in the mirror selection section, I chose mirrors from the same hosting company (It seemed that you had to select at least 2 of them, one from each). My reasoning was that if the mirrors were out of sync, that if I chose the same hosting provider then they would at least be in sync with each other, even if behind the global ones.
That install however, didn’t have the right options. When I re-ran it, I got a different mirror list and didn’t have 2 of the same host so never got past the metalinks error.
I solved it by running:
sudo pacman -S pacman-mirrorlist antergos-mirrorlist
sudo mv /etc/pacman.d/mirrorlist.pacnew /etc/pacman.d/mirrorlist
vi /etc/pacman.d/mirrorlist and selecting a few mirrors locally, uncommenting them.
I then restarted the cnchi installer and selected to leave the mirror list alone. The install continued