Lin,
I would stay away from CFDs and other derivative instruments (including a lot of ETFs out there).
The only ETF I would recommend to you is GLD (SPDR Gold Trust). It is listed here in Singapore as well as the NYSE in the USA. The reason that this particular ETF is relatively sound is that it actually buys physical bullion and safekeeps it....a lot of ETFs out there simply take exposure using futures and other derivatives.
To understand why you need to avoid a 'paper' or 'digital' substitute for Gold (and buy actual metal itself), you have to fundamentally ask yourself WHY it is you want to own Gold. That reason is that confidence and trust in Fiat currencies is eroding....in such a World, all bets are off and paper contracts can be rendered 'null and void' by Government, or your counterparty could simply not honor their side of the deal.
Gold is REAL money, always has been and always will be as long as human beings control this World.
Here is a good place to start if you want to learn more:
http://www.gata.org/