Better thread to ask this question.
You can all ways replace the two 2114Ds with two LME49860, or even get a pair of LME49990s.
Save a few dollars and get the Superlux HD-669, should give you a decent enough sound and well under your budget. has a detachable cable and you can also replace the cable with any mini jack (3.5mm) extension cable.
Yes, do not wast money on an Xtreme Audio, older chip design that uses extra software to compensate for it's older design.
Xtreme Gamer, about as old (and cheapest price) as you can get and still have decent support for EAX 5.0.
The Xtreme Gamer is a little bit newer design over the Xtreme Music and the Gamer is smaller.
I retested my DT-770 80-Ohm cans yesterday, bass did not seem overpowering. You could all ways save some money and get some decent headphones, like the Superlux HD-668B. There are cheap enough that it would be easy to sell them to a friend if you decided on getting more expensive cans. Read all the reviews on the HD-668B on this web site. I'm still pushing the Asus Xonar DG, that with the HD-668B is still well under your budget.
If you invest in a Asus Xonar DG (PCI) sound card (cheap price and there is a $10 mail in rebate this month).
It has a decent headphone amplifier, which should improve the sound quality of any headphone you get.
It also has Dolby Headphone 5.1 for both games and movies.
For a headphone, a used or refurbished (eBay) Beyerdynamic DT-770 Pro 80-Ohm, really nice bass.
Total should be under $150, maybe as low as $120.
Conan the Barbarian (2011), it's like someone took and made for T.V. script and gave it 8 times the normal special effects budget,
and then found out it had too much blood and tites to be able to play on the SyFy channel.
I'm really hopeful that there will be a sequel.
I'll buy the extended Blu-ray version when it hits $9.99.
I would assume if you got a "gaming PC" with an optical output, you could just plug the Astro MixAmp in to that.
Or for a cheap sound card, an Asus Xonar DG, which comes with a decent headphone amplifier.