Fake antiques (which include fake antique tea sets) are nice. The quality isn't bad -- just realize that, regardless of what you are told (and irrespective of the "authenticity" seal from China on the bottom), what you are getting is fake. Pay accordingly, and feel free to bargain prices down to what you may think is a ridiculously low level.

Tea makes a good souvenir -- it's packaged quite differently from what you're used to in the west. However, tea ranges dramatically in both quality and cost. Some teas cost hundreds of dollars a pound. It would be helpful if you can get some local to advise you if you're unfamiliar with the different grades and qualities.

Avoid electronics and camera gear. The chances of getting scammed are great unless you shop at a reputable store, e.g. Fortress, but you'll be paying more than what the item costs via good mail order in the U.S.

Chinese liquors also make good gifts but, for the more popular brands (Mao Tai, e.g.) you need to buy from a reputable store, as there is much counterfeit product around. It used to be that you could recognize the genuine alcohol goods by the hologram on the box, but the holograms have been counterfeited in the last few years so they no longer provide guidance. A good supermarket will have the real thing.

I don't know where you got the idea that HK was Japanese. Except for a brief period of occupation during WWII, HK has been British and Chinese for two centuries, and is now a Special Administrative Region (SAR) of China.