What kind of visa should I apply for four to six month stay in Hainan , correct documents and how long it takes?

Hi, I am a Singaporean. My husband is a Malaysian (Singapore Permanent Resident) working in Hainan, China. I am planning a four to six month stay in Hainan to visit my husband, with multiple entries as we may visit Hong Kong and Macau. 1) What kind of visa should I apply for? 2) Which is the correct form to use? and 3) How long is the approval process? Thank you