Single or Double or multiple visa entry

We are singaporeans n would like to know which type of visa should we apply:

1) 2 of us going for 1 week only n any visa require for: Sin/Guangzhou/Macau/Shenzhen/Hongkong/Guangzhou/Spore

2) which type of visa? Single/double or multiple visa entry?
2 of us going for 3 weeks Sin/Guangzhou/Macau/Shenzheng/Hongkong/Guangzhou/sin