In my view the best area is definitely Hong Kong Island, especially near Central. Even more specifically I'd recommend 'central midlevels near the escalator'. Soho West, nearby is pretty good. I would recommend an older walkup block with redevelopment potential. These places go for a slight premium over those with no potential but offer a "lottery ticket" bonus, because if someone does want to redevelop he will have to persuade at least 90% of leaseholders to sell.

It is relatively easy for a foreigner to obtain finance for this kind of purchase both from HK and overseas banks, lending up to 70% of value. The interest rates (courtesy of Ben Bernanke) that are payable mean that there is usually no problem at all with interest cover. Yields are around 6.5%.