OP,
Couple of additional thoughts.

China and Asia are a photographer’s dreamland. Don’t expect to do it all in half a dozen trips, less to say 1 trip. The key is to concentrate on just couple of regions to minimize flying.
While in Guilin/Yangshuo, you can tag on Longji Rice Terrace (or others in the same area). All can be done in 3 nights/4 days.
As far as Guilin, Yangshuo and Longji, some images can be found below:
http://stefanofoto.smugmug.com/Asia-...jiang-Li-River

http://stefanofoto.smugmug.com/Asia-...ilin/i-WHf8zc9

http://stefanofoto.smugmug.com/Asia-...aces/i-P4gp3qB

Toss in a couple of places to consider (on top of what up-posts suggested), while you’re in the southwest China, how about LiJiang (the city) and Dali, both are in Yunnan. To fly there, need to transit in KMG (I think? Not sure if any direct flight KWL-LJG).
Some images from LiJiang & Dali can be found on this (2011) trip report:

http://www.flyertalk.com/forum/trip-...dventures.html