Get an R4 (or m3 simply I heard they are basically the same thing) for NDS stuff. I have one, its excellent, plays all my backed up NDS games. As for homebrew, its worked with a couple emulators, SnezziDS (I think) and NES ( I forget which emulator). The DS scene doesnt have perfect emulators, but they are getting there. I never tried any homebrew games, so I can't help there.