How can I get back if I have a single entry F?

I am (US citizen) currently working in (Guangzhou) on a business visa and want to travel to Hawaii to meet my family coming there from the States. I am on a one entry. How do I leave China and then get back into the country. I'm leaving out of Hong Kong. Do I just apply to get back in on a new visa when I return to Hong Kong from Hawaii? and is it possible to get a multiple entry business F when I return from Hawaii as I want to visit Hong Kong from Guangzhou once I have returned from Hawaii or should I just get a tourist L and apply for a business F after my visit to Hong Kong. I will be working in Guangzhou until September 2013.