I did a lot of research on bag options for my Fatboy as it's my primary mode of transportation, and I need room for laptop, etc. for daily commute.
I went with hard bags from Dyers Fiberglassworks mounted with Easybrackets. The bags were $469 shipped, and I paid a local shop $150 to paint them. Easy brackets were $150. IMHO, money well spent...
Quality of the bags if outstanding - thick fiberglass and while a little on the small side, they carry what I need. I fit a bike cover, rainsuit, laptop, medical kit, bungee cords, and lunchbag each day, and there is still room for small stuff. I can also fit my xxl kilamanjaro jacket in a bag (big coat) on one side when I get off. I wear a fullface, so can't say whether you could fit a half-brain bucket in or not, but I bet it would fit.
Best of all, I can take the bags off quicly and easily for cleaning or for cruisin' - simple twist of a key and lift em off. Takes about 10 seconds a bag!
I tried to post pictures, but evidently I have to have 5 posts before I can put pics or links in a thread.
Pics are available at photobucket dot com. My photobucket alias is Fatbaggster. You can search on "people" and you'll find my album.
Forgive the new guy....
While I can't yet post links or pics, I was able to create an Album and upload pics. In-case you're interested.
The Dyers hardbags are some of the nicest I've owned.