you want a bright light?
run a square 12v tomos headlight.
they are bright, have hi-low funtion and OEM parts are still available.
find the simple square 12v box voltage regulator that come on tomos, they either work or don't, and you need another. i think treatz have em
grab some motorcycle LED's from autozone/napa/cap/whatever, they are all wired internally with a rectifier.
, thats your best case scenario.
if you wanna keep your cool round headlight, get a 55watt sylvania bulb, and if you clean the glass/brass bell of the light you can use solder to hold it in.
all my personal tailights i make, out of 1" vinyl braided tubing from home improvement stores, with two LED's jammed in each end. i wrap this tube around the back of my seat (so you can see it from the sides as well as the back.) solder everything.