Mr.Sandro Garavelli, sorry to reply you a litte late. It seems that there is not a specific Chinese visa for you which allows you stay in China for 6 months. Generally speaking, Chinese visa allows a stay duration of 30 days. The Study Visa, Work Visa, Residence Visa & Journalist Visa of China allows a stay of one year or longer. However, you can't get the Visa. I advice you to apply for Tourist (L) Visa. Please write your need on the Visa Application Form, maybe the visa afficials will give you a longer stay duration rather than 30 days. After you arriving in China, before the expiration of stay duration, you apply for extension at a local public security bureau.