There are a couple of different locations you can find lighting systems, I have used landing lights form RAM RC and they are easy to install and look great. http://www.ramrcandramtrack.com/rclights.html

Also Aero Accesories From Dino Digiorgo is another place. I have not used his systems yet but as for customer service Dino is great to work with.
http://www.aero-accessories.com/Builders.html