Green teas have caffeine in them, and if it's the addiction to the caffeine you're trying to break, you're best to avoid them.
One thing that I enjoy is a pot of NON-tea: hot water with a citrus twist to it.
Chicory was used by the Natives of North America as a coffee; it's sometimes used in coffee to decrease it's bitterness (and if it's good coffee, it's not bitter to begin with).
And if you want the definition of a headache, go cold-turkey on the coffee drinking: you'll have a monstrous headache by day 3 that simply will not quit pounding.