I'd use a malleable, but sturdy plastic for the appliances (Buttons, strum bar, frets, etc), and a better circutboard for the fret buttons. Maybe throw in your own design there. Also, use a more durable spring for the whammy bar. Use either a mercury switch or a hard-wired switch for Star Power, or, if you want, use an FX-Like pedal for Star Power/Overdrive. But using either a fiberglass hybrid or wood would probably work the best.