I'm not sure about the flour substitute. I am curious as to why you do want gluten in it?
As for the coffee, that's a weakness of mine, I drink the teechino brand from the health food store. They have different flavors of which I only like 2, but the ones I like are really good! Anyhow, it's not coffee but a coffee substitute. Coffee substitute sounds pretty nasty but it's not at all! You can order it offline at their site or get it from your local health food store.