Unfortunately, none exist right now. At least, none with HDMI inputs for audio - you can find dinky boxes that take optical and coax and do Dolby digital and DTS, but no current unit does TrueHD or master audio formats.
5 years ago, Sony had the HW7000DS I believe which were wireless surround headphones, but they're no longer sold.
The closest to a headphone processor we have is the much delayed Smyth Realiser A16 which costs a whopping $3500 but will process all audio formats (including 3D like Atmos and dtsX) into any set of headphones. But it is delayed and not out yet.
If you have a htpc, there are various software solutions that work, including out of your head (OOYH) to give a realistic effect.