Chain and bearings (wheels and Race) can sometimes be a bit crap if they're still OEM, if in doubt change before you leave: SKG bearings and a DID VXGB chain minimum. When you upgraded the suspension did you use an Indy top bolt kit... some have had there's bend under hard use. When I upgraded my suspension I put the beefed up Indy kit in too (see ADVrider).
Tubeless wheels make repairing punctures easy, this will probably be the thing that will hold you up, so a stop 'n' go pocket tyre plugger kit with a electric pump is a good idea but spare tubes will sort you out in an emergency, and for that you'l need minimal tools. I wouldn't bother with an extensive tool kit or spares generally if their are dealers/mechanics nearby (for example the fuel pump and ring antenna are talked about but are mostly ok on the F800GS).
The bike is an all round bullet, as long as it's fit and serviced when you leave it'll keep you moving. If things go tits up try to look at it as an opportunity, that's when the adventure begins.
