If you get the repair manual, you don't need the owners instruction book. You have a great trip planned, now is the time to get used to serviceing the bike. Do a search on modifications you can do to make it better (all bikes have inherent problems) and start to do some jobs on it to optimise your tool kit and knowledge. If you can't repair/service the bike you'll be at a big disadvantage, even in a well supported country like the US. Being fairly old technology, the beemer is relatively easy to work on.
Tim ('91 R100GSPD)
The only baggage you carry should be in the panniers