The CAG-O-Matic picked up a $40 price drop on these. I will try to find some reviews.
Both are $80
Home Theater Pack Surround Headphone + 5.1Channel Headphone Amplifier
PC Pack: Surround Headphone with External 5.1 USB Sound Card
Both are $80
Home Theater Pack Surround Headphone + 5.1Channel Headphone Amplifier
PC Pack: Surround Headphone with External 5.1 USB Sound Card