Reply to Production soundcard for djing?

Hey guys,

I've seen much guys using Native Instruments soundcards for djing and stuff and seems really appropriate but in my case, I would like to have a production soundcard also. It's all the same? I've seen some soundcards online that have two inputs and two outputs that are essentially production soundcards but would they work on traktor for example?

The idea is to use a controller and an external mixer (like my vestax vmc-004 if i don't find a buyer for it). I really only need two channels on the external mixer and so... I only need two outputs on the soundcard. I don't really care about inputs.