Can confirm my workaround by disabling internet in the 18.8 ISO, worked for the install. So to anyone else unable to install, get the 18.8 ISO, turn on internet, right when you get by the internet check disable it again. Then go all the way until it asks you to wait while it refreshes repositories, enable it again. Now rush through the last parts of the install before it closes the installer down, and hopefully the installation should start before it closes down.
Spent all afternoon and night with the same issues.
18.9 is stuck on installing bootloader.
18.8 updates cnchi to a point where it is unable to start giving the maxminddb error. I think I may have found a work around of turning on and off internet at the right points, so I could get through the install without it updating cnchi. Currently installing this way and hoping it will work.
Very disappointed that an iso this broken got installed, and then cnchi updated with no checks for backwards compatibility. There should at the very least always be some way to install antergos.