Buying a laptop (Singapore)

Hello guys

I'm currently living in China, but I'll be in south east asia for some holidays and during my stay in Singapore I was considering to purchase a laptop (I was supposed to do it in China, but I found difficult to get original windows O/S in english).

So I was wondering if someone could give me good tips about where to buy original HP notebooks and how to deal with the VAT reimburse in Singapore.

Thanks
Rafhael