The local ONLINE trading platforms that do US Stocks (that i know of) are CIMB, Hong Leong and Philips Security.
Are you planning to trade or invest? Trade = in out or Invest = buy and hold?
If you are trading, you need real time quotes. And I'm not sure the above mentioned Online Trading Platform provides that. You could also get real time quotes on Google Finance and Yahoo Finance and trade on local platforms. Another platform which you can try is Etrade.Com. I've not used the US version but I have used the Australian version. Not sure if its the same!