Only downside to those wireless headphones above is that they have build in lithium ion or lithium polymer batteries. They are custom to probably that brand/model of headphone and replacements will only be available thru the manufacturer (you'll probably have to ship the headpones to the company). So expect replacement batteries to cost $30-40 my guess. You'll need to replace the batteries in 2-4 years (2 years for heavy use)
I haven't looked into the market of wireless headsets too much (I've had only one in my life, cheap RCA ones). Depending on your budget, I'd recommend headsets that use either AAA or AA batteries as these will always be readily available.
