Thank you for informing me of this program as I was unaware of it. As to locate posters for your classroom, contact http://www.loveofreading.org/. They would be I believe the correct people to reach about any posters that might be available.
I might also point out another set of posters that your students might show interest in. They are from the American Library Association and have famous people holding books while promoting reading. The posters can be found here: