pretty sure it was a standard DS card that he said he was buyingYou don't need any 3DS flash card at all, unless your objective is to play backed-up copies of your 3DS games. The software required to develop and run 3DS ARM9-mode homebrew is all in this thread, for free. For coding examples, download everyone's source code and read up. You will, however, need a DS-mode flashcart to run the installer.