I had similar requirements for my camera. albeit in a compact scale I got the Sony W1. I agree with the others. For travelling the long distances, I'd highly recommend AA NiMH batteries. Charging points are few and far between (esp in eastern asia). I hate the fact that you need the camera (and sometimes cradle) to charge your Li-ion batteries. pah!
Perhaps the level of camera you were shopping for charges the batteries in a cradle. But I don't think there is a camera with a proprietary battery mentioned in this thread that charges the battery in the camera.
If I were going to Mongolia the long way I would take Li-Ion batteries if I had the choice. Charge them before you leave home and they are still fully charged when you get to Mongolia. Good spares are cheap. $40 worth of spares plus the original are going to fill between a Gig and 2 Gigs of memory according to the file size unless you shoot at low quality. One night with electricity and you are back to full power.
I think the larger problem is memory storage. Get lots of memory or a portable storage device unless you are taking a laptop. CF memory is the cheapest way to go for gobs of memory with SD second.