That is good you are already dealing with DC. Most bikes I have seen without a stator rewind can only handle about 35W bulb and still keep the ignition and everything working right.
My interest was in doing this with led, probably an ssc p7. HID is of course another option, as you probably already know, trailtech is one company that makes an HID helmet light.
I haven't seen anything here specifically for a motorcycle mount, but plenty of super bright bike lights that would suffice.
Something like
this could be modified as either a bike mount or helmet light. Mounted to the bike, especially to an aluminum frame part would be ideal as it would help draw heat away from the unit.
If you wanted to stay with incandescent it would be simple to use any mr16 type bulb and housing, a decent cable and gland and mount it where you wanted.
I am thinking a good place to start will be finding out what your charging voltages are on your bike, and how many watts your stator is. Since you do have a battery, unlike my bike, you could exceed the wattage of your stator for a short time, but it wouldn't take long to run your battery down.
Have a look at what some of the other member have acclompished and see what interests you.
Take a look at these:
http://www.candlepowerforums.com/vb/showthread.php?t=213141
This one is one of my favorites, Trout did an excellent job!
http://www.candlepowerforums.com/vb/showthread.php?t=209991
Very basic:
http://www.candlepowerforums.com/vb/showthread.php?p=2657802
And have a look around the automotive forum and electronics as well to get some ideas for 12v circuits.