If its all for gaming, you can get yourself a headset with an USB interface which eliminates the need/use of any sound card.. Check out the Creative Sound Blaster Arena (very good gaming grade audio) and Logitech G35 gaming headset (visualised 7.1 audio).. I vote for the Creative model among the two..
G35 over the Creative, hands down. Its one of the few USB sound solutions that I actually ended up using (and am still using) for any length of time.
Still, remember you are loosing audio quality by going USB. If your not a serious gamer, you'd probably want to go the soundcard route. MY usual recommendations of the ASUS Xonar D1/DX and HT Omega Striker still stand.
^Good choice for that budget.
I have a sound card already (AuzenTech Bravura) but needed to buy a headset because of moving into an appartment.
First I tried SteelSeries 5H (7H were out of stock) but they weren't very good... quite dissapointing. I then made the jump to Sennheiser PC 350s, which I got for $60 off (awesomely lucky timing) and THESE are bar none the most amazing headset I can imagine. The sound is super crisp, lots of bass, and best of all the sound positioning is unbelievable. I'm talking not just hearing things in front, behind, or beside, but it actually does a good job of placing the sound above or below you too so it's like full on 3D sound effects... and it's actually only stereo. So impressed.