Hi,
My name is Roger Fedyk. My profile shows my long experience in programming (as well as music and writing).
I have extensive experience in PDF creation particularly using iText (Open Source). However, I am also an expert in low-level PDF creation, not that those skills are required for your project.
iText has both Java and C# versions. I would write the original Windows code in C# which is almost word-for-word compatible with Java and then provide a Java source version. There are open source QR libraries to use.
I have quoted a time 10 working days which includes testing and updates/revisions.