h1b ap back to Shanghai

My H1b will expire 2010 and I have AP now. I am planing to go back shanghai to visit my girlfriend, and we plan to get marry soon. When I go back shanghai, should I use H1b? I heard that my H1 will expire immediately if I use AP, is that correct? here I am asking two questions:
1. What kind of visa should I go back?
2. What is possibblity to get a H4 visa in shanghai in our case?

Many Thanks in advance, I know this is the best place to ask help here.

Have a goog week.