Get one of the illustrations from Jack Feels Big printed on canvas.
It's a little bigger than A3 (which is like two pieces of A4 paper side by side). I've had one at home for a while and people think it's a painting and ask if they can get one!
You can request any illustration from the book, or from the Sophie version of the persistent story (perfect for a determined little Judoka. I'll be in touch to confirm what image you'd like.