I would go with the brighter headlight recommended by Glider, the Osram 80W/100W and from German Auto @ approx. $12 plus shipping it is a BARGAIN improving rider vision. Headlight modulators may work, but to me at night, as oncoming traffic it certainly would be distracting and perhaps hazardous.
Try the lamp change first, and the money saved could be used for other things like brighter tail light (LED ones are brighter and more efficient.