If you want to look for a mortgage on your own, there are many mortgage plans and different types of protection against rising interest rates available. Some banks will give a mortgage of around 90% of the value of the property, others only up to 70%. Some waive valuation and handling fees and others will tailor a mortgage plan for you with long repayment facilities and mortgage insurance.
Mortgages are also available through some government organisations like the Housing Authority (2712 2712) and the Housing Society (2839 7888). The Hong Kong Mortgage Corporation has a list of approved mortgage providers you can check: www.hkmc.com.hk.
A very important factor you need to take into consideration when buying a property in Hong Kong is currency risk. If you are being paid in a currency different from the one you are paying the mortgage in, you can be adversely (or advantageously) affected by changes in the exchange rate.
If you are on a local package and are being paid a salary in HK$, a mortgage in the local currency might be preferable for you as this removes currency risk. For many expatriates HK$ interest rates are lower than those in their home country, with interest savings up to 5% per annum. However, borrowing in HK$ also involves risks, so it is best to get some professional advice beforehand. Some international banks offer foreign currency loans they you can take out against a property back home.