I think the jacket looks great too. No doubt about that in my mind.
This, however, is why I'm hesitant. I'm thinking that flannel on flannel would lack the contrasting textures that make a solid sportcoat / solid trousers look work properly. edmorel made an excellent post on the topic here - http://www.styleforum.net/t/308954/on-solid-and-solid-like-jackets-shirts-ties
I also think that tweed would probably be a better choice but I'm willing to be convinced otherwise.