Reply to Traktor with two external soundcards for FX send/returns

I'm currently in the process of setting up a new workflow, just playing around with new gear and having fun
to see what I'm going do to this year and to see where it takes me.
I currently have a 2 channel mixer with send/returns, pair of 1200s and Audio 8 from NI.
At the moment I'm not believeing about taking it to the club, just believeing about the possibilities.
Since I would love to use 2 channels of DVS and 2 channels of internal playback / sample decks so
i'm pretty quickly running out of channels. Since the Audio 10 has only one extra stereo channel it would be no help. Could I use an another external soundcard for two FX send/returns and has anyone tried it under windows?