The one thing that is hard to get in China is access to an unmonitored internet!
But apart from that, as I recall there is not a wide variety of food in the supermarkets, but then your taste may not be what the brother would enjoy.
A quick search came up with the following:
"If you pay a visit to a Chinese family, it is smart to bring gift for the hostess like a bouquet, cosmetics, or scarves. Toys, candies, books are good for the children if they have them. Some practical items might be a good choice. During the traditional festivals, you can bring wines, cigarettes, tea, candies, fruits, or some of your local products. However, there are some tips for you to note, which is considered to be unpropitious:
a. Clocks should never be presented as gift to others, especially to elders.
b. Pears can not be sent to couples.
c. People who are unwell may not be given medicine as gift.
d. Intimate items of clothing may not be gifts for friends of the opposite sex.!
Though I can't really imagine you would be taking him some underpants! 