You want the best. Avoid the soundcard. Avoid the expensive high end motherboards with onboard headphone amps.
Get yourself an external USB DAC. That'll give you superior sound. A nice one is the M-Audio super dac. Another nice one is the Emotive Ego series. The DAC won't have fancy dolby software or cretive CMSS vitrtual surround sound for headphones. That's why soundcards cost so much, they have all this fancy software that's not good. Just install Razer surround for free and get virtual surround sound. $20 unlocks the full version. More expensive solutions exist such as out of your head but the razer is good enough for the price.
Now just get any set of headphones. Hit up a music store that sells guitars and stuff and go shopping. I recommend a pair with a removable cable so it can easily be replaced when broken. AKG, Seiheisser, Audio Technica, Grado, Sony, Shure, etc... Lots of good brands out there. Depends on your budget. Hit the store and see what they have.
Now your missing a mic. If you have a webcam you can use that. If you don't have a webcam and want one, problem solved. Otherwise the Blue Yeti or Snowball are the better ones.
A USB headset is basically a cheap DAC, Dolby Headphone software, and a cheap pair of headphones all rolled into one gaming package. If any of it breaks it's garbage. Buying the components seperately as above gives you professional sound, and a product that could last forever. Good headphones can easily last forever as they can be repaired and rebuilt. Seinheisser for example will always have replacable parts and ear cushions. And for music and movies they will be superior to a USB headset.
You could always just use your onboard sound for now and just get a pair of headphones. Upgrade to a DAC in the future. Also note the DAC can also be purchased at a music store. The Emotiva one must be ordered firct from them, but something like an M-Audio or Dragonfly can be purchased in music stores.