As a reply to Colbach on the short thing , im 5'4" and have a f650gs fl model its perfect for me , I can touch the floor with both feet flat the weight is low down thanks to the location of the fuel tank. I have ridden it off road through rivers and it coped no problem. I think weight is the biggest thing when looking at a bike and mpg I get 80 mpg from my bike and it cruises at 70-80 mph with ease for me its nearly the perfect bike and this from someone who swore never to buy a beemer ....
oh and if you need a mechanic on your trip I'd be happy to help lol
Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do.