Sir, my wife is Chinese, I'm British. We are going to travel and visit my Wife family to China.

Hi Peter, if you want to get a long-term entry permit, I advise you to apply for the Q1 type. Though it only allows you to stay for 30 days in PRC, you can get a residence permit with it. The residence permit can be valid for one year to three years. If you have this, you can travel without any entry permits to PRC frequently.