More information needed on Start Lights for SCX Digital

Hello,

I purchased PCLP and the related hardware for use on my SCX Digital track. My question is, where do I purchase the type of external light shown on this link (http://www.pclapcounter.be/other_light.html), what type of phidget should I purchase, and where can I find a DETAILED wiring diagram to accomplish this?

I have searched the forum, but I can't seem to find the specific information I require.

Thanks very much in advance,

Brent