I can think of only one light that has captured my attention in the last 6 months, like truly captured it. I would venture to say this would get there attention 100% guaranteed:
I'm guessing its under $100 to build, but the labor involved, now that's a different story! I have faith in you though!
You could always go for the Nitecore SRT-7 or the Sunwayman F40A I guess and take the lazy route!