So, one way to go would be to have two or three
reed switches attached to the back of my aluminum floor board, with a bar magnet affixed to the back of the accelerator. The lower switch (nearer the hinge at the bottom of the pedal, would be actuated sooner, and the one closest to the top of the pedal would be actuated last, since the top of the pedal has a longer distance to travel.
I agree with Chris that you're almost never feathering the throttle on the track. You'd probably just want two switches: one to indicate some throttle, and the second to indicate full throttle.
Or would Radio Shack solution be easier? I have
zero knowledge of electronics. And by that I mean
zero. I'm going to need very specific guidance on this.