I don't know of any special patterns for using with picture blocks. I think most people just pick a quilt block they like and do it in the wedding colours along with the picture blocks. You might like to look at some paper pieced sites for wedding objects? I've seen some awesome PP bride and groom blocks. Maybe something like that in the center, then your photo blocks and pieced blocks around them. I did see one quilt where they put the photos in the center portion of a Double Wedding Ring quilt but that might be more than you want to tackle.