Some of the ghostbuster kits I've seen have cool lights. You could search around for who they use. Another easy option is finding a toy that has lights you like and then just taking them out of the toy. The long way would be programming a chip like the arduino to activate whatever you want, and have lights for a backpack and helmet controlled by one thing.
The more specific you are in what you want to do, the easier it'll be to help. Do you have any pictures you can share?