S2 type visa or L type

Hi my partner (unmarried) has been offered a job in China. He is currently staying & working there just now. I am going for a 3 week holiday in February and then moving there myself in April. I have applied to a university in PRC and the course does not start until September. I will then be able to get a student X type. My question is what type should I get before this time? Is it possible to get a S2 to cover both the February trip and then April - August as I see this can last up to 180 days. I could apply under the 'other private affairs' category as we are not married. Or should I apply for a tourist L type for the Feb trip and then again up to 2 times for my stay from April - August until I get the paperwork to apply for a student X type. The information on web sites etc is very conflicting and confusing!