You can modify a very easy to find Radio shack AC adapter to supply power to the JVC. I'll dig around and see if I can find that. Edited to add: Meh. I'm old and I saw it perhaps a couple years ago. You could try this guide: http://www.instructa...ough-AC-power./
I have a JVC sitting around that I used to use with my gaming rig and a pair of HD 595s. Almost the set up you are going for... again, I bought the Japanese version so I could plug it in.
The sound quality between the Dir 2000C and the 595 was very close, with the Dir having the added benefit of being able to output Dolby Headphone /many/ headphones at once. I got it thinking that I would buy another compatible headset, plus the wired jack for the 595, so that I and two friends could game in the living room without driving my wife crazy. ... Again, they don't seem to sell the unit any more.
The 555s are a good choice. Be careful with them as they aren't designed to survive really harsh treatment. If I was buying again, I'd go with the Astro 40 as I think it allows you to fine tune how loud voice chat is in comparison to the surround field.
Edited by Gourd, 05 November 2009 - 05:50 AM.