Most of the fix should be much simpler. Pay them each $600k, indexed to inflation.
That should make them pretty resistant to bribery. Your quality of life really doesn’t improve much past that $600k point, even if you’re maintaining two houses. (And the justices aren’t representatives. They don’t need a second house.)
But yes, their tax returns should be public as well.
When all your planes come back with bullet holes at points A, B, and C, where should you add additional armor?