I personally have both of these flashlights at home and they are fantastic.
http://www.amazon.com/gp/product/B00...ms_ohs_product
http://www.amazon.com/gp/product/B00...ms_ohs_product
However, I have not tested them on a robot for goal alignment purposes. Why not try a few different options (ring lights with a camera, LED flashlights for 'photon-cannon' style) and see?