I haven't heard about white coffee until I came to Malaysia. The Malaysian Ipoh white coffee is actually your regular coffee beans, roasted in margarine. The name white coffee is usually associated with Ipoh because it is the place where it was originated.
When I went to Penang three years ago, I bought the Ghee Hiang Pure White Coffee. Compared to other brands of white coffee I've tried in Malaysia, Ghee Hiang Pure White Coffee has a nice soft flavor, although the caffeine is really strong... keeps you awake for hours!!! My foreign friends like it a lot.
Ghee Hiang is well known for their sesame oil, and the Tau Sar Pneah (Chinese biscuit with green bean filling). I couldn't find their White Coffee and biscuit in KL though.
This is the traditional coffee cup and saucer set Chinese Malaysian like to use for their coffee.