Don't know how much dirt riding experience you have?
But if you are starting out without much experience, then weight of the bike is the biggest thing. The singles will be a lot easier to learn on, and even easier to pick up. I'd advise you to get the single. And find those small country roads rather than inhabit multilane mindless transport corridors that will disappear when 'beam me up Scotty' becomes available
The KTM (or Husky etc) has better suspension than the Yam (or Suzi, Honda for that matter). However the KTM will be more maintenance that the Yam (etc). Don't worry about power output, you'll use what you have and have fun with it. Suspension on dirt is where you get safety and speed.
Welcome to the dirty side
The photos and old ride reports I've seen of Afghanistan are really good and make me want to go ride there. Fortunately there are quite a few other places with similar qualities to go see, ride and experience. Get home safe.