I recommend a really good book:
''First Overland'' by Tim Slessor - published in 1958. It tells the story a trip from London to Singapore and back, overland using Series 1 land rovers.
My choice of vehicle would be a Series 2a - nice strong gearbox, cheap parts and you don't need a laptop 'puter to talk to it (unlike the Defender TD5). 'puter no good in Tibet where even roads are a luxury...