From HKIA to Guangzhou Science City - fight arriving at 1835 on Oct 30th

I have been given some options for train travel from HKIA -- believe that I will be too late to catch the train from Hung Hom Station given the time to pass through immigration and collect my luggage. I am looking for options. It is not my first time in HK, but my first time traveling to the mainland from the airport. The late hour is of concern to catch the right connection. An option is to stay in HK and travel to Guangzhou the next morning - perhaps even by ferry.