seat
I recently had Gennadi designs (gtx1.com) lower my seat bottom. They take out some padding and redo the leather cover. It looks completely stock to the eye, but it added some 2" of headroom, which now makes it quite ample for me as I am 6'4 - 6'5". Before doing it, my hair touched the roof and the top of the windshield was in my line of sight.
The seat bottom is firmer now since there is less stuffing, but overall still reasonably comfortable. I would definitely recommend them. It was expensive, but they did a very nice job.