Thanks to everyone for the helpful responses! The community here is really awesome.
I think I'm going with the Acekard 2i or the R4i Gold due to price.
1. Are there any differences between those two cards? Acekard 2i vs. R4i Gold?
As my attention to these two cards, i found that R4i Gold ( www.r4ids.cn ) team is a little hardworking than AK team. Why? The R4i Gold kernel is updated nearly every two weeks.
2. Is R4i Gold the same as R4i Gold Upgrade revolution? Found here:
http://www.gamesyeah.com/r4i-gold-upgrade-...on-cid-194.html
Not the same, i checked the site by searching ' R4i Gold ' , their link for R4i Gold (www.r4ids.cn) is http://www.gamesyeah.com/r4i-gold-card-for...are-p-1702.html
3. Where is the official site for Acekard 2i?
My answer is http://www.acekard.com/
4. Any etailers that you would suggest that sell legitimate products? I was thinking of buying it here:
http://www.gamesyeah.com/acekard-2i-for-ni...dsi-p-1509.html
Checking the AK2i official reseller section, this site is listed . you can buy from this site .
Maybe a US based seller will get it to me in time for Christmas.
But you'd better choose express, no any site can promise you that the goods can arrive before Christmas shipping by airmail .
5. There used to be a special requirement on the SD card like Made in Japan Sandisk. Is that still the case?