Amazon.com: Tascam US-4x4HR 4 Mic 4IN/4OUT High Resolution Versatile USB Audio Interface for Recording, Streaming, Podcasting, Songwriting : Everything Else
M-Audio AIR 192|4 - 2-In/2-Out 24/192 USB Audio Interface @ The DJ Hookup
RUBIX44 USB Audio Interface 4-In/4-Out for PC/MAC/IPAD | Roland Pro AV | Leisuretec
Universal Audio Volt 4 - Milk Audio Store
M-Audio AIR 192|4 USB Audio Interface | Sweetwater