After dis research and planning for some months, finally bought the iRobot Roomba 560.
Since the US dollar exchange rate is quite low now and was thinking of buy directly from US website. However, the shipping charges, power voltages converter and warranty issues. Finally, decided to bought from this guy from eBay. He is quite helpful and friendly in the HardwareZone forum to advise on the iRobot thingy.
I was quite surprise the iRobot could “suck-up” as much as dust/hair from the floor. I can also schedule iRobot to do the cleaning when we were off to work during the day.
See how my iRobot in action
iRobot return to home base after job done.
I can have clean floor everyday now.