Hi,
let’s turn this around a bit. What is it you are trying to achieve? Do you want to use DJ software, yet keep on using your analogue Behringer mixer? In which case you need something to control decks (like the Trakor X1 or, if you want jogwheels, the Denon S-1200) and something to route the sound from your laptop back to your mixer (Traktor A4, Rane, other brands).
If you want to use turntables or CD players to control your DJ software via timecode, you need a specific soundcard (that is DVS approved for the DJ software you want to use). You don’t need an extra controller like the X1, but control with timecode is somewhat limited. No cue points, loops or such.
If your plan is to really use DJ software to DJ, then my advice would be to consider getting rid of the Behringer and just getting a decent DJ controller. It will be all-in-one and be way easier to set up and use than any combination of modular controllers and sound cards. Especially if the whole point for that is to keep using the mixer, which – in my humble opinion – is not special enough to warrant that kind of effort.
So, let us know what end situation you are trying to achieve and on what budget and we can probably give you better advice.