Well if you go with colored LED's I know at Jameco.com you can get them for about 20 cents apiece. That is where I have gotten all mine and haven't seen any issues. They use UPS for shipping. As for mounting them I would recomend mounting them as far from the key surface as possible. This will give you light a better chance to diffuse. Alos it might be a good idea, but time consuming to paint the inside of the keys white. This will help reflect extra light around inside the key.