For simple storyboarding, there are various dedicated programs out there, I have an old copy of Poser I can use to generate stills of various setups in conjunction with photoshop to make storyboards.
Menus can me mocked-up in photoshop, as far as the "look". Visio can be used to diagram links.
But before you get all high-tech and "dog-and-pony"...
Consider that a strong, well-developed concept should be easy to convey in one, not-too-packed page of simple text. After all, you only get a log-line in TV guide. I would concentrate first on generating the best possible description of the concept using just words.
If you start with that, the other features you seek are going to be an additional booster to your effort. I wouldn't try leading with the glitz stuff though, unless this is truly something that could not be described accurately in words.