xtrajack,

I am confident that you could wire your own brake light, however, since the Nashbar unit is on sale right now, price-wise you can't do much better. Using a micro lever switch, you have three connector terminals--C, NC, and NO, which allows them to be wired in Normally Open or Normally Closed position. Connect your hot wires to the angled C terminal, then connect the load wires to NO terminal, since you want the light to go on when the brake is pressed and the lever switch's rod is pushed in. I've used red as the "hot" wire and black as the load wire in this illustration. I've used the two holes in the body of the switch to run small zip ties to connect the switch to the brake cable.