I would echo Tembo on this one. Buy what's cheap in your country. Over here a 300Tdi 5 speed can be had for less than 750 dollars. It would most likely fail our road safety test in that state but we have one of the toughest in the world...
I remember the first time I worked stateside, picking up an XJ for less than a day's wages, working on it for two weekends and it lasting me the 6 months until I left; I sold it for a weeks wages. Great vehicle. Simple... Stick with what's cheap
My first trip to Africa was in a Series 2a 109 station wagon. The 2.25 petrol donk had more piston slap than up and down motion. It leaked oil like the Exxon Valdez. I paid less than £500 for, spent a bit of time getting it about right. Tamanrasset and back (in the days before they metalled the road) and virtually nothing broke. Parts were cheap. It used more fuel than you could imagine in your worst nightmare. But to get parts I went round scrap yards, and refurbed stuff I might need or that were better than I had...
So listen to the guys. Yes a D1 is the finest overland barge you cab get (except a LWB G wagen with a 617 Turbo); but it needs a 200Tdi and a 5 speed and they are even getting rare over here. So find a cheap, easy to fix, common 4x4 and then adapt yourself to it. Even a Samurai is workable - just take a big tent, preferably ex military and canvas...
Good luck