Oracle Migration Approach (Open source vs Vendor Specific)

Hi All,

In our company we are looking to migrate oracle db to postgres , now since
we dont have any expertise in Postgres in our organization so we are
planning to go
with AWS aurora or EDB postgres so that we have helping hand in
migration(in dev and dba) while we get mature in postgres ... do you guys
think after 1-2 years if required it will be easy to move from EDB or
Aurora to Open source Postgres assuming we dont use AWS services OR would
you suggest to move to Community version from the start by taking
support/consultancy from other companies like 2nd quadrant and etc?

All our developers are experienced in pl/sql so I assume it will be easier
to learn PL/pgsql ,isnt that right? so far only things i dont like about
PL/pgsql that validation of program units doesnt happen until you run it
... though i did find extension plpgsql_check to achieve that to some
extent.

Regards,
Sandeep