I have my suspension simular to yours and i weight in at 13.5 stone.
I find my front pushes and has a tendancy to run wide into a corner, i have added some rebound but it hasnt helped much - i think its my riding style - i leave my breaking quite late even on the road - this causes the bike to "spring" and and makes it run wide -
When exiting the corners it also runs wide if im a little hard on the throttle - i think this is becuase i need a harder spring at the rear - if i wind up the rear perload to much - it will have no sag left in it - it maybe worth getting a harder rear spring - it could be the bike is squatting to much in the corners - but im sure someone will have something to add or correct me if im wrong
Sala