I purchased Lunar ATX case (YY-5402) from Yeon Yang. Since the product is not widely available from many sources, this is the place to buy Yeong Yang.  
As a retail store, this is just yet another Yahoo store, but, since this place is a company store, it gives me better confidence in the service than other retail stores.  
As far as the product goes, I think that Yeong Yang's cases are very solid and honest products.