AFAIK, the brightest commercially available yellow front light that flashes is the Dinotte amber light. I purchased one as my daylight "be seen" light during a tour of Yellowstone. Works best in overcast/rainy conditions. I leave it on my commuter/early morning trainer all the time.
My front lights are a bar mounted Jet HID and a Dinotte 5L on the helmet. I expect to change the Helmet Dinotte for a 20w halogen in the near future.
While I agree with cycocommute in principal about the flashing light getting washed out, I believe that in flashing mode the Dinotte puts out more light than otherwise. I'm a great believer in the "the more the merrier".... at least as far as lights go.
I purchased the Dinotte amber light for use in poor visibility conditions as opposed to night time use. If I ran as much light as Bekologist does, I doubt that I would use the Dinotte.
I hope this is helpful in thinking about your issue.