H1-B going back to China for visit

Hi,

I currently hold H1-B visa. I intend to visit China early next year.
I live in Seattle area and I am thinking of applying visa in US consulate in Vancouver.
Can someone tell me whether I can get the multiple-entry visa as I have to come back to US before I go to China.
Also, what is the prospect of getting visa in Shanghai, China if I apply in US shanghai consulate?
What option is better?
Your help is highly appreciated.