Afaik, the Browser for it can only be from the official sites, and the 2nd hand section of EBGames(or similar.)
Same goes for the stylus, however 3rd party ones work fine.(I'm using a wide one from an old LCD PDA, and a long thin calligraphy style one from some touchpad my parents bought in HK)
Also, If you just buy the DSL version of it, and own a twi-wing, I think you can "implant" the chips n stuff into an old GBA cart.