The only LED I know capable of that output is the Luxeon Star. It's freaking expensive, and requires, as the article mentioned, a special heat-sink setup.

If you go to Target and look at their flashlight aisle, you'll find a 3.9W aluminum LED flashlight (White) for less than $60 that uses the same brand of emitter but has even higher output. Find a red filter and you're all set. It might not last a full 3 hours, but if you're only riding an hour per day max in the dark, it doesn't matter much anyways.