I don't think the device really matters. All the models are compatible for Gen IV and V. You have to enter the first, really long code into the Action Replay. Where there are those three asterisks in a row, instead put in (for example) "001" if you want to get a Bulbasaur. Once you put it in and start up the game, press SELECT and you should find Bulbasaur in the wild. Once you catch a Bulbasaur, save your game, shut it off, get into the AR part, and replace, in the code, 001 with the next pokemon's code you want. Let's say Metagross. You'd erase 001 and type in 178. Start the game, press SELECT at the point where you see your character, and TA-DA you will encounter Metagross in the wild.
No, you won't have to enter the first, incredibly long code in every, single time. You will only have to replace the *** part with the pokemon's code and the pokemon will appear in the wild after you press SELECT. I'm sorry that if you want to get all the pokemon possible it will take a while. But there is no cheat where all the pokemon will materialize in your PC. That'd be simpler, wouldn't it be?