Rift9437 Brave or Chromium should do the trick, in case you're interested. I used Brave on Linux to install GrapheneOS.
One other note - you mentioned planning to get a pixel 7. Nothing wrong with that, but I'd consider a 6 series if I were you for the following reasons:
1) Limited reports of camera lens cracking/exploding on the 7's. This is likely a manufacturing defect, and could have been limited to a bad batch. Other manufacturers like Samsung have had almost identical issues in the past.
2) GrapheneOS does not appear to utilize the additional features of the improved camera on the 7 series, even when using the Google camera app. I believe it has something to do with the tensor chip not being utilized fully as it should. There was discussion about this just a few days ago. Don't misunderstand, it will still take good photos, but you will not have the full capabilities of the stock OS, and apparently portrait photos can take an unusually long time to process. This would not be a dealbreaker for me personally, but thought it worth mentioning.
Cheers, and welcome aboard!