well, it is simple - good headphones make more impact than a good sound card, but any decent headphones are useless without good sound card and even the best sound card on the planet won't help you much without decent headphones.
and keep in mind that headsets usually suck. most of them do - some more, some less and some /read. all nearly ALL USB headsets/ suck to the extremes... and also, virtual surround is a gimmick - any decent sound card can do better.
so, if I can get you an advice - get some decent headphones and pair them with a cheap clip-on microphone.
here's a link for you to browse>
http://www.overclock.net/t/1014902/ocns-most-recommended-audio-products