If you have DS Lite I recommend getting it, I ordered mine from
[Only Registered Users Can See Links. Click Here To Register] the bundle M3Lite + Passcard 3. You just have to upgrade the firmware from here
[Only Registered Users Can See Links. Click Here To Register] and you can download games from here
[Only Registered Users Can See Links. Click Here To Register],
[Only Registered Users Can See Links. Click Here To Register], or
[Only Registered Users Can See Links. Click Here To Register].
Some pictures of my DS Lite + M3 Lite
I use A-Data 1GB MicroSD, you should check
[Only Registered Users Can See Links. Click Here To Register] for the compatibility of MicroSD, you want to find Castlevania Test:
5 (make sure its 5 else some games that you run will be slow)