I would do it on my GSA, no hesitation because I'm 6'7 and I would want comfort too, dirt or pavement. That said, you can't go wrong with the KLR650, DR650 or SV650 is even better. I do like the DRZ400 too...nice bike and easy to work on. Like others have said, go with what you are comfortable with, there is something said to bikes that a simple and easy to repair. Good luck and have a great adventure!
Don't blame me, I voted for the MOTHMAN!