Hi everyone, need a little help! New to the dj mixing world and was lucky enough to get my hands on a Xone 92! All I have with me is my Mac, headphones and Traktor Pro 3. I intend to mix with 4 channels, what sound card is best and is that all I should need for this set up? Just and interface to use my xone with 92, why is everyone getting these K1 ect are they nessasry?