Check out the ESI U24XL, a USB audio interface & soundcard, for a great way to get quality sound between laptop and mixer or amplifier.
The ART DTI (Dual Transformer Isolator) will eliminate ground loops as a potential hum
source and provide an interface between RCA-, XLR- and TRS- terminated cables.
To add a couple of microphones, the Focusrite Scarlett 4i4 is a USB audio interface with quality soundcard.
The Allen & Heath XB-14 and ZED-14 mixers each have one USB-B input socket.
The Allen & Heath Xone:96 mixer has two USB-B input sockets.
The Soundcraft Notepad-8FX small-format mixer has one USB-B input socket.
