I've thought about using something like an X-keys programmable keypad. It's definitely something I'd love to setup to load comp templates, node favorites and run scripts. It would probably require a bit of coding but could be quite efficient.
Let us know if you end up using a G13 and how easy it is to setup with Fusion. The thing I like about the x-keys keypad is that you can print out your own icons/labels for the buttons.
Steph