Great bike and you are on the right track. For our size of guy the bike is way under sprung. If you have any experience with decent suspension setups and it sounds like you do then the 800 is going to be very lacking if you push it off road at all.
I note that you are in WA. You should really chat with Alex at Konflict Motorsports. Guy is a real pro and the setup he did of my front forks is very sweet. http://konflictmotorsports.com/
Except for a good bash plate all the rest are wants. Plus if you are cheap (like me) a seat and decent suspension is going use up a lot of the kitty.