querying a linked PostgreSQL database in SQL Server 2008
If you are OK with the reports being run directly off of the Progress database, look into SQL Server Reporting Services and the Report Builder 2.0 in SQL Server 2008 R2.  If you can deploy Reporting Services 2012 (part of SQL Server 2012) and you've got SharePoint 2010 installed look into using PowerView so allow people to build reports off of data sets which you've pre-defined as part of a data model.

If you need to get the data into SQL Server then you'll probably want to look at building a SQL Server Integration Services package which would then copy the data from the needed tables into the reporting database on a set schedule.