+1 on the Zero Gravity, I don't have a LL but know it's way quieter than the stock was.
I'm 6'1" , it's an '02, does have Helibars that changes the position a bit too...
I have a similar issue from time to time. I got grip puppies (neoprene grips) which dampened some of the vibration and it's mostly gone away. Also I notice when I wear gloves with minimal padding it's worse.