Reply to Adding a Maschine?

So, My birthday was yesterday and I am going to get some new gear. I have the S2 and Headphones+ a launchpad... And I want to add a set of rokit 5's, a maschine mk1 (my friend is selling it to me for 175$) and Komplete 8.... Do I need to get an external soundcard to use the rokits with the maschine or can I use the S2's soundcard? advise?