Need new headsets.

Hey there, I was looking to buy a new gaming headset because mine broke, I found the plantronics 777 5.1 , plantronics 377 and the creative fatality (proffesional ), ( i was looking for the range 50-100) . But I have a question, I noticed that there is only one difference between 777 and the 377 and it was the external sound card dolby 5.1; If i have a mobo with an integrated sound output of 5.1, would it be the same sound experience between the 777 and the 377? Or the external sound usb thing makes a big difference compared to the integrated audio of 5.1 channels ?
Which of the three is better?
If you guys can recommend other pair of headsets between that range, Ill be thankful.