i use a dstt card for my ds lite and besides waiting for new updates to come out for it i have had no problems ive herd good things about the cyclone card but havent tried it myself as far as playing gba games i have a slot 2 device it was pretty cheap under $10 if i remember corretly you can usally get a package deal that includes the card, slot 2, and a micro sd card for a pretty good price once you have the card you can then get a program called moonshell that you can play mp3s/movies ect. i tried moonshell when i got mine (about a couple of years ago) but it was kind of a hassle because you got to convert your movies to a certin format and the ds screen is kinda small to enjoy movies on i havent tried any new versons of moonshell because i got other things to play movies and listen to mp3s with i hope this helps you out a little bit because i really enjoy my ds its a fun little system and i dont regret getting it