To 1: With a DS or DS Lite, you need an R4 or similar flash cartridge. With a DSi or any 3DS or 2DS, all you need is a computer and a sufficiently sized SD card (depending on how many game backups you‘d want to safe on there). For softmodding a Wii or WiiU, all you‘d need is an SD card and a sufficiently large USB storage medium for the game backups, btw.
To 1: With a DS or DS Lite, you need an R4 or similar flash cartridge. With a DSi or any 3DS or 2DS, all you need is a computer and a sufficiently sized SD card (depending on how many game backups you‘d want to safe on there). For softmodding a Wii or WiiU, all you‘d need is an SD card and a sufficiently large USB storage medium for the game backups, btw.