I'm thinking that its probably a DIY project since it appears that there aren't any "bolt on" replacements. I did something similar on my valiant, so it can be done.
Here's some sources for a variety of different LEDs that you may be able to make work for your application, you might just try to focus on the tail/brake fixture since theres no real saftey issue with the backup lights, and not worrying about them would simplify your project. good luck! -pauly