I can't speak for M3, but supercard should run all those nds roms you mentioned (I just checked the compatibility list, as I haven't tested them yet). There are signficant issues with some gba roms (slowdown, apparently due to slow onboard ram). Nevertheless, it's probably the best value for what it can do...
Check out their site as well:
http://www.scdev.org/Yeah, the commercial passme devices should all be fine -- nothing really exposed. I'm not sure about the build quality of the passme device sold on the
www.dspassme.com site. The commercial versions include: Magic key, Superpass, EZPass, Passkey (they all should slot nicely into the ds). The latest versions, such as the Superpass 2 (based on Passme2), are made for those who have newer ds firmware (you don't have to worry about that in your particular case). However, they still function with an older ds by acting as a simple Passme1 device.
For the new ds lite coming out, one will need a passme2 device in order to make it compatible. That's one area where a Passme2 device, such as Superpass2, would come in handy.
BruceG
EDIT: You also need an original ds game cartridge to insert into the passme device. Later on, you can install the flashme firmware on your ds, so that you may remove the Passme device from the nds slot (the passme device will allow you to install the flashme application, if you should so decide)