Unless you make up the return home your only real option is Pirates of the Vistula as that is the only one in Poland.
It might be worth it for you to pick up Free City of Krakow at either Amazon
http://www.amazon.com/Free-City-Krak.../dp/094358051X
or DrivethruRPG
http://rpg.drivethrustuff.com/produc...ts_id=435&it=1
That module is really the centerpiece for the Polish Modules.