Visa for enter Shanghai during transit time. please show us the cost for each of us.

Hi,
We are a group including Sri Lanka, Thai, Myanmar and Vietnamese students. We're studying in Japan and have a president credit. Our group will go to Singapore for conference and our expected flight (China airline) will transit in Shanghai about 8 hours. At that time, we intend to enter Shanghai for sight-seeing (about 5 hours).
So many thanks