Hey there Don,
Just in case you're in the Wrenching section but not looking at the "Build your own speedo/tach" thread you'd started, I'm opening this.
The link you provided seems a bit too technical for me to understand (or at least my initial impression of it was that way). I'd love to have an effective shift light for less than $100. Do you have a guide or instructions for making one that's aimed at the electronically challenged?