on behalf of my Omani friend, what type of visa to be applied to go for purchasing building material

this request is on behalf of my Omani friend who wants to go to China, Guangzhou for purchasing/searching building materials for his new home. he wants to know type, charges, type of visa for his dependents (including child below 2 years old), photo size/background color, how many days will be required to process the visa and what else will be required.