The wzr-hk-g300nh is the only Buffalo that does USB sharing.
Buffalo Technology - Comparison Charts - Wireless Comparison Chart
Personally, I like the Cisco Linksys WRT-160NL. It has the storagelink function that you are looking for. But I am not up to date on the price of this model in HK.
Linksys by Cisco Wireless-N Broadband Router with Storage Link WRT160NL