I've also been looking at the DS3000 for late night PS3 gaming but my budget is limited to sub £100 and as yet haven't found them at this price. A used set
went on ebay for $130 this week so there could be a deal out there.
I rejected the Senns listed above, for one, the lack of optical input and perhaps more importantly they do not list these (Senns) as 5.1 headphones. For purely gaming and thinking on FPS's specifically (eg COD), directional audio is going to make a huge difference to the experience.
Check out the
Ear Force x4s which are along the similar line to the the Sony's if you're looking at primarily gaming set of headphones.
Fingers crossed for some deals in the sales - I wonder if Zavvi stock them?