I've gone for the Colin Chapman "Add Lightness" modus vivendi......i've left the tread rubbers off all together and put m4 x 12mm 316 polished button heads complete with 2 nylon washers and a nyloc nut in the holes. Think it looks well, sort of thing you might expect to see on a Supersport.
If your nuts are on show they've got to be sexy......all bumper irons, back and front, secured with 316 polished dome heads as far as the eye can see, although i've got them all fitted with black nut covers at the moment, not sure if they are staying, to be decided.