I am arriving late on a Saturday night to SIN.

Want to see the sights for a day or so then move on to KL before heading to Langkawi. Week later I need to retrace my steps and fly SIN-SFO home.

The fares on Malaysian flights seem high for the short hops...what alternatives do I have? Is there a budget airline that goes SIN-KUL-LGW? I saw the Silk Air flights and they do not seem very budget. How about the train? Any other thoughts?