In order of preference:
@GrapheneOS on a new Pixel
@LineageOS on almost any other Android, including older models
A Linux phone (not everything will work)
I would be skeptical of the bevy of new “pre-made privacy phones” that are going to pop up in the wake of current events. At best, it’s just an Android phone that someone bought and installed Graphene or Lineage on before selling it to you. (Installation isn’t very hard, and there are step-by-step instructions you can follow yourself.) At worst… who knows.