Screw the R4 and R3 we live in a new era xD there's new Flash Carts out
that do the job nicely and are cheap and have frequent updates.
I suggest you buy the new
iTouchDS Flash Cart or/and DSTT Flash Cart
Here are the links if you are planing to buy it, i purchase mines from there and i got them.
DealExtreme: $10.70 New TopToy DSTT Multimedia Card for NDS and NDS Lite (Supports SDHC) Only 11 USD
DealExtreme: $17.20 iTouch Multimedia Flash Cart for DS/NDS Lite (Europe/USA Edition) Only 18 USD
You need to buy the Micro SD card buy sepertly i suggest you try STAPLES
they sell the 8 GIG Micro SD for 24 USD, AVOID buying off BestBuy they
always rip you off.