I found theese new American Library Association READ poster featuring Dakota Fanning as Jane reading Eclipse, and Taylor Lautner as Jacob reading New Moon. Both of theese posters are new Stills from Eclipse and New Moon!
22" x 34"
Unfortunently, this is as big as they get!
source; http://www.alastore.ala.org/detail.aspx?ID=2919 (aslo order them here).