I'm also new in 3DS scene, but from what I understand, there are only 3 regions for 3DS, Japan, EU and US. Asia included in US region list.
So ASI set (MY/SG set) = US set, the only different are the charger and have PIN code to register at nintendo club website.
I have US region machine and Im glad I bought it, cause I can get point from club.nintendo.com, every US game have a PIN code that can be registered to given a point in the club nintendo website. With that point, we can redeem an apps or games on the eshop (this depend on the nintendo redeem program).
But everything still up to you, MY set have official local warranty, us machine mostly only have shop warranty, and games for ASI (MY/SG) is a US region game, it have a label like this on the game card: XXX-XXX-XXXX-USA, I have super mario 3d land for ASI and it is a US region game, but it come without a PIN code, so cannot register it to the club nintendo to get point.
Added on March 5, 2012, 11:47 amMy nintendo 3DS prepaid problem was settle today, play-asia.com give me the wrong code, and they send me the correct code to me today, only different in one number, they mistaken 9 with 6, haha.
I can buy pushmo today!! wiiu wiiu wiiu!
oh by the way, dont make teh same mistake like me,setting the region to washington and kena tax! sigh..