1000 and very large does not match in database land We have tables with millions of records at work. 1000 records is peanuts for good database servers.
MySQL Administrator can import from SQL Server. Doesn't PostgreSQL have something similar?
With SQL Server Management Studio you can export to several destination types. CSV is one of them (as Flat File Destination), perhaps you can use that as intermediate result. Unfortunately there is no ODBC destination. Perhaps you can find and install the necessary drivers to register PostgreSQL as a destination.