A couple of guys have posted links to Riding House parts before but I thought I'd point out they offer a HID kit which includes a specifically designed bucket.
I emailed them and for the S2R/S4R the costs are
HID Light Kit -- 49800 yen ($510.00)
HID Bucket -- 18690 yen ($191.00)
I couldn't gather given the language barrier whether the Light kit included a new reflector along with the lights at that price I'd expect it to. If I was seriously considering it I would have pressed further for info.
The bucket looks pretty good (and similar to what I had fab'd and welded last week).
(http://www.riding-house.com/products/ducati/fiber_parts/img/zhh_010.jpg)
http://www.riding-house.com/products/ducati/fiber_parts/zhh_010.html (http://www.riding-house.com/products/ducati/fiber_parts/zhh_010.html)
Cheers
Seems like it's the stock lens for left side drivers in the pic.
I'm guessing from the website (translated), and the pic, that it's just for the bucket.
actually its a headlight fabbed to accept the longer Bi-Xenon bulb. that cylinder sticking out the back is longer than stock.
the second price is just for the bucket.