I found three resources on the internet that may help you find the right light. Candlepower Forums has a bike light database that includes lights that produce at least 80 lumens.
Even better is the Eddy's Bike Shop in Ohio website, they set up a darkroom and photographed the resulting beam from their stock of headlights, below are samples of two different lights.
40 - 50 Lumens ------------ 200 Lumens
And finally the Planet Bike Light Finder is a similar web page that features their own lights.
I should note that we are finding that only about 40% of the urban core riders are using lights at all, anecdotally that number plunges way down for working cyclists in the suburbs and the resort areas. Getting everybody to use any grade of lighting at night could significantly reduce the number of bicyclists injuries and fatalities.