Anyway - was a Steelseries USB 7.1 thing wasn't it?
Generally, I'd go with the above advice but you might struggle on budget. Do you have a soundcard? If you get USB headphones they basically bypass the soundcard so you don't get any benefit from it.
Assuming you want to use it for gaming, I'd stick with Xonar / X-Fi series. You need specific models for surround simulation over headphones though.