I pre-order from singapore and I'm at malaysia. Just call to the number 1800814963, choose your language, choose whether you have PSN ID or not, then finally choose WARRANTY department. As far as I know there is no such thing as SONY set or Malaysia set (And BTW, this is SONY PS4, there's no other *Brand* PS4). Even if it does, all SEA sharing the same warranty, meaning if you go thailand holiday 1month with your set purchased from Singapore, you can still enjoy the warranty at Thailand.
I don't have receipt or invoice number too. All I got is Order Number, and it works fine. I'm sure there's a order number reference for you to track even if you pre-order somewhere.
They ask for your:
1. Serial Number (15 digits which you can find it at the box).
2. Date purchased.
That's all. They didn't even ask where I bought it so it's clear that it's not a problem.
I suggest you first call SONY Malaysia Service Centre @ 1300881233, ask them about the SEA warranty. Then you call PlayStation Asia, they are more pro than SONY Malaysia.