I hear Google Pixel unlocked with Graphene OS installed is a good option. Haven’t tried it yet though
Discussion
I think this is the Way… just bought a pair and my IT buddy is setting them up. Says Graphene was super easy and smooth to install. Make sure the phone is unlocked AND OEM unlocked was his main advice
Oh, and I went with Pixel 6/256GB from swappa.com for about $230, including shipping and tracking