Which device is the best for DS-lite?

I have DS lite and I need to change my flash-card which one is the best R4,M3, Edge or others ? any suggestions?

At the moment I'm using an iTouch2 Enhanced, which is the successor to the M3 series. For your money you get a pretty GUI, real-time saves, slow motion, cheat database and supposedly 100% compatibility after anti-piracy patches - everything I've tried on it has worked perfectly so far, including Portrait of Ruin and Animal Crossing.The only thing is that it took a week to get to me from Hong Kong, but that's to be expected. I was using an M3 Simply before that.

CycloDS evo is the best choice for "Hardcore" gamers. If you want regular stuff just get a DSTT or M3. DSTT is cheapest however. (I can send you a link for a 5$ DSTT with free shipping)