You're right, the PCC is not installed by Peachtree. The PVSW install they use is a very minimal install.
You can use DTO/DTI to create the database name/data source name from within your application or during installation. It does not require the PCC and would work with PSQL as it's installed by Peachtree. Check out the Pervasive web site (http://www.pervasive.com/developerzo...ods/dtidto.asp) for more information about DTO/DTI.