I'm planning to buy my first bike, for the purpose of exploring China (mostly rural areas), and camping. I'm not a speed freak, but I would like to be able to ride uphill at a reasonable pace. My bodyweight is 64 kg (141 pounds), and I will pack light. Of course I want a bike that can endure long-haul trips. My ideal price range is within 8000 or so.

My feeling so far is that a 125 might be too weak uphill, but since it's my first bike, 150 should be enough. Thoughts?

Also, is engine displacement even the best indicator of performance, or rather, should I be looking at max power (8/10/12 kw etc.)? And, why is that some 150 bikes have a max power of 8 kw, whereas others have 10? That seems like a rather significant difference for two bikes with the same engine size.