Go to Fleabay or Amazon and search "cree bicycle headlamp". You'll find dozens of them for $20 and up. I would stick to the single light per unit since you have redundancy if something goes wrong. Get at least 2 of them...one for the bar and one for your head. Three is even better since they are cheap.

One caveat: The lumen rating is way off. They don't put out 1200 lumens. More like 800. That's still very bright for a cheap light. Many "be seen (but not really)" lights cost much more than these.