Its really all about what you like when riding, but Id go with the METZELER ENDURO 3 SAHARA they are made for Africa really grippy soft tires, I had the Continentals on mine but took them off the first chance I got for off roading.
I also went over to the Metzeler Touraces for Street riding, much much better then any of the others I tried out. I normally ask people with the same bike but different tires if I can have a quick ride to see what we each think about the others tire choice.
When are you leaving on your trip? and what are you currently using for road use?
Hope that helps.