Not that on point - but I just ordered a flash from Amazon, and am getting it delivered via vpost. I just an email saying that the flash has reached vpost in the US, so hopefully I can get it soon once i make the payment for vpost.
If you try to get the item sent direct from Amazon to Singapore, then it probably can't be done. I tried it for the flash, and it said that there are geographical restrictions or something and the order cannot be processed.
The problem will be if the flash is faulty - usually even if the seller (Amazon in this case) has a flexible return policy, you still need to send the darn thing back to US at your own cost, which is gonna cost a pretty penny and may not be worth it at the end of the day. I had that issue with something else (not camera-related) I bought from the US (luckily I found the problem after I took the thing apart and managed to fix it).
Hope this helps!