I found this LED light at Harbor Freight that fits the hole in the Dillon 550 tool heads perfect. Problem is that the light is a POS and doesn't work all the time. I'm trying to build or find something similar that shines light down from the top so you can see in the cases. Maybe a LED light that's on a flexible neck ?
These guys have shelves of cheep 12V power supplies - switches and connectors: http://www.reuseum.com/