While I would be happy to be corrected by someone, to the best of my knowledge this is simply not possible.
The way headphone jacks tend to work is creating something of a short-circuit so that the signal never actually makes it to the speakers. Beyond that, you'd need a similar ability in the software to be able to send audio output to a specific hardware port, and very few programs offer this feature. XBMC is quite possibly the only example I can come up with off the top of my head.
The infrastructure to do this simply isn't there on either the hardware or software side. At least not with consumer level equipment. If you were willing to invest a couple thousand dollars into some professional grade audio equipment, you might be able to do it, but seems to defeat the purpose I think you'll agree.
You may wanna shop or look around if you're interested in looking for other cheap sound cards. Whatever works best for you. On the matter of headphones if you ever decide to get gaming headphones with that surround sound 7.1 stuff, it's a gimmick, avoid it like the plague. Quality stereo headphones + CMSS-3D or Dolby + good sound card = better.
Kind of funny, my friend buys these Astro A40 headphones for so much money, which are supposed to be great and meant for gaming, I get superior results out of my stereo headphones with quality drivers and sound card.
I would not recommend against the Corsair Vengeance 2000 though since your only gaming, and they are stereo headphones technically with virtual surround sound.
If you do want quality headphones for music(lossless) and gaming there are lots of great options for stereo headphones by reputable brands like Sennheiser, Grado, Audio-Techica, etc.
Headphones like the Razer Tiamat are huge gimmicks, 10 cheap drivers packed into headphones too? NO THANK YOU!