I missed the new (blue) model of KJ's bike. Looks great for touring. I guess he upped the gas capacity?
I've never done any bar mods for vibration, but I think that birdshot would be the smallest dia. lead pellets and would be the most weight, short-of melting lead ingots and pouring it into a bar end, w/the other blocked-off, of course. The cement idea is probably the cheapest.