We used the company Enterprise DB for our conversion from Oracle to PostgreSQL.
https://www.enterprisedb.com/downloads/postgres-postgresql-downloads
1. Despite what anyone tells you, there will ALWAYS be SQL that works in Oracle that fails in PG. You will need to recode those blocks.
2. We paid for tech support. It might be a good idea for you to do the same, at least until the database, embedded SQL, database scripts, and all other SQL-based components have been converted and tested successfully.
3. PG databases are NOT case-insensitive. When you define them, they store data EITHER as upper case or as lower case. Use lower case.
Good Luck,
Olan