Don't use one of these intermediary companies that charge an arm and a leg for something you can easily do yourself. http://www.chinese-embassy.org.uk/eng/lsyw/chivisa/
But I assume you are going on Legend otS - do you actually need a visa - what itinerary are you doing?? You only need a visa if your cruise starts in China - you don't need one for your visit Sanya.
We too are going on the Legend (Singapore to Shanghai) visiting Vietnam, Cambodia and Sanya and we are very confused regarding visas. Will we need any for these countries and if we do, can we get them on the ship or do we need to get them before we go? An guidance will be much appreciated.