usb dj controllers

as in, those fake little decks for controlling software. any of you use that use them got any recommendations? I haven't bought vinyl for over a year because I'm cheap and not that serious about djing, but I really miss the feeling of beatmatching. one thing I do like more about mixing in ableton is being able to use 3 decks though. how does that work with these kinds of controllers, can you set up a button to switch it between virtual decks? I looked up the stanton dascratch on their website and it reads almost like they want you to buy one for each deck... :confused: