Acekard 2i is the best choice to go.
Just got my AK2i today. Ordered it last Thurs in Uk.
I am looking at getting a card for my DSi, I have been looking at this:
M3i ZERO for DSi - DSL - DS UK STOCK
On the Acekard it says something about the DSi has to use firmware v1.3 to get the card working so no good for me now.
Acekard 2i For DSi, NDS & NDSL