I ran these cheap CREE light bars last season and they worked great:
I used the Cyclops Explorer battery powered LED light bar and dual helmet lights on my YZ450F last year. REALLY awesome lights, can't say enough about the explorer especially. The throw to weight ratio is crazy.. super light and small, small light battery, throws for hours. And it mounts / unmounts in about 5 minutes. I have had a few of the amazon/ebay el cheapo helmet / bar mounted lights and they never held up very long, as well as their rated output is completely exaggerated compared to the cyclops stuff. If you ride with me you know that I usually come back in the dark after a real long day. I need things 100% reliable.