I could neither find (nor afford if I could find) the kind of headlamp I wanted for my bike. I'm sure I'm not alone in that situation either.
But that didn't mean I couldn't build a reasonable facsimile. Below is a pic of what I run. Since the time this pic was taken, I have put on an outer lexan lens to kind of raise the authentic look. But it's really just a 6v bike light inside there, powered by a bunch of Energizer Lithium AA batteries. I have an album on this forum that shows a little of how I made it from: a stainless steel toilet brush holder, stainless steel sunglasses case, and the tank from a longish holiday cookie tin. The housing holds the lamp; the tank houses the batteries and switch - within easy reach. It's really quite bright. And sitting rather high, it aims well.