VB6 - convertion from Access database to PostgreSQL

I have been asked to take a VB6 application that use an Access database and convert it to use PostgreSQL.

From what I can see the VB application connects using DAO and also JET/ADO!

Not sure why it has both

If I do convert it to PostgreSQL do I have the option of standard ADO access or do I have to use DAO?

Also, what are the performance considerations?

May thanks

Jonathan Blitz