Buy used, and/or buy an “a” model.

GrapheneOS is clearly the ideal ROM/OS, but alternatively there is another privacy and security centric ROM that supports a lot more devices, with the trade-off being it’s not GrapheneOS.

Check out DivestOS and it’s supported device list to see if that’s a better fit for you. It’s from the same developer as the Mulch and Mull browser forks.

As far SafetyNet/Play Project and other anticonsumer “security attestation” features, some bank apps will work fine, what others won’t.

Does their website provide PWA support?