Rmx 1000 for Ipad with Djm 850

 Hello, I am interested in buying the rmx 1000 app for Ipad. I have a djm 850 mixer, and I wanted to know if I would need an external soundcard to connect it (as the djm 850 has already a soundcard). I would like to use the app in two ways:

-With my djm 850 and two xdj 700

-With my djm 850 and traktor

I also would like to know if I need the lighting usb to connect the ipad, or if it's enough with the normal usb with I use to load the ipad.

Thank you