I wouldn't bother with Halogens at this point. You only need two components to make your own LED dynamo light, ignore all those complicated circuits you find. You just need a 3 watt or more LED and a full bridge rectifier. You can get the full bridge rectifier at Radio shack. You can get the LED with reflector and everything by buying one of those "Tatical" LED flashlights. For instance, I went to Lowes and bought the Task Force 3w Cree Flashlight, took out all the battery driver circuity and just soldered the LED inputs directly to the outputs of the full bridge. It works just fine, barely even any flicker unless you are going slower than walking speed.

To get a tail light I stuck a 3w LED to my back rack (with a heatsink) and wired it in series with the front. Now I have a 3W front and rear light.