separate USB cueing device on supported controllers/mixers?

I am looking to upgrade some of my gear. I am looking at finding a mixer that has multi USB inputs One for main out and one for cueing. Anyone seen anything like that out there? The other thing I am considering is one of the controllers that has built in mixers with outputs. Does it show up as two different audio devices in the DJ pro software? How does the cueing config work on a supported controller with mixer functions?