I have Z type, need to apply for S1 or S2?

I have been working in China for 4 years with a Z type that is renewed every year. My husband and I we’re just married and we will be here for another year. He has a student X type but lives in a different city and would like to just come stay with me for our last year here. Which type should we apply for S1S2? My visa/residence permit will expire in June, and then will be renewed again for another year. So I’m not sure if we should do S2 now or do S1.