Will these speakers work for djing? (link in description)?

You should provide more details about exactly what kind of DJing you are going to do. If you are planning to do pro DJ work these are highly inadequate. No offense but you might get laughed at by pro DJs. These things are intended for home karaoke style use and will not be able to adequately fill a room like a large banquet hall where most DJ events, like wedding receptions, are held. If you are planning to do your DJ act just to entertain friends in a living room or small home or office parties they might suffice. As for hooking them up to your Macbook I don't see why not. They have a standard audio in and a USB in as well. As for the system configuration; you will hook the speakers up to the laptop and the DJ controller will control it via a MIDI link.