The Scotts/Ohlins steering dampner is a good one (I have one) or the GPR V2 each with a sub mount.
The 6.6 gal Acerbis tank...cheap at $250 US. Change the gearing and add the cush drive rear wheel, ala 640 adv. $650 US.
Some type of radiator protection.
The Wolfman luggage is better than the rack and a hell of alot cheaper. I used the small explorer. $150 US
Windscreen......yes a must for that distance......Make it the rally fairing.
GPS....hardwired just to be safe. eBay $150 US.
Buy tires along the way. Tire balls maybe an option instead of numerous tubes and crap.
Thinking out loud here.......Hell if I could take 6 mo off I'd be with you on mine. Remember people always pack shit they don't need or ever use.
Wish Jim would chime in......