Where to find 700c tires in southern China or Hong Kong?

[ulysseg]

I am actually based in the Guangzhou area (Guangdong province, China). Next week I leave for a long trip in central asia and I just realized that I have to get new tires. But the 700c size is not common in China.

Would anyone know where 700c tires can be found in the Guangzhou area, or in Hong Kong (probably more chances in HK)?

Thanks!

Ulysse