Hi, Im not sure where you can buy cards pre-loaded but if you want to buy
a blank card and load it up with games yourself its pretty easy to do.
I recently bought an acekard 2 for my girls DS Lite from here: Gamewrecked.co.uk - Video Games Consoles Parts & Accessories| Wiikey Fusion| Acekard 2i|Supercard Dstwo
The cards are genuine and it only took 2 days to arrive.
If you still have your R4 card, it might be that you need to update it to
the latest Woods firmware to get it working again: http://www.digitalworldz.co.uk/26977...r4-1-36-a.html
Worth a try.