PSA: If you're running a business and some databases store vital customer or financial data, consider EnterpriseDB (EDB). It funds Postgres and can be used almost like Oracle DBMS. And definitely send encrypted differential backups to Tarsnap for really important data.
... or any of the other companies that provide support and actively contribute to the PostgreSQL project, such as Cybertec, Data Egret, Crunchy Data, AWS, ...
I wouldn't choose any PostgreSQL supplier for their similarity to Oracle DBMS (why would you want to buy into that ecosystem?); as long as it behaves just as vanilla PostgreSQL it is good enough for me.
