'05 Muano - DVD Headphones

I recently got a used '05 Murano with DVD. The wireless head phones are missing, and I was wondering if anyone can tell me how well they work, and if anyone knows where I might be able to get some replacements? Do they all work off the same signal, so any pair should work with my system? There doesn't seem to be a headphone output jack on the dvd unit, so I believe my only option is to play the movie sound through the audio system or pick up a new set of head phones. Thanks, LLS