Hard of Hearing Headphones for TV


My dad hearing is going downhill. He has become unbearable to watch TV around. His complaint about hearing aids are that they make it louder but not clearer. After a ton of research, I've come up with a couple of questions that I need help with:
1-A company TV Ears makes a great claim about transmitting in mono for wireless headsets. They stated that since everyone's hearing loss is not equal side to side that it works best. Any thoughts? I could probably do this with Y cables for any headphones.
2-Sennheiser has some really nice wireless headphones, 410, for TV. Anyone play with these?
3-AKG has a wireless system, 840, that seems very nice but a bit cumbersome.
Who has played with any of these? I'm not afraid of price. I even lent dad my AKG 701's but the cord and size were annoying for him. It looks like I'm going to be spending anywhere from $75 to $300???
Thanks for the help.
elevick
Thanks for the suggestions. Keep them coming...

My hopes are to get him headphones he will be happy with. Then he might actually get on his audiologist to find him hearing aids that work as well or better than those. We all get stubborn and cheap in our older years.
Okay, Elevick what I have is a Sennheiser Freeport 820 S system (you can probably do a google search and find out more). On the box it says RF wireless listening system for use with hearing aids. However, I am not sure if the additional wires for connecting to special types of hearing aides is included. There are no headphones, but the box states that any headphones can be connected to the portion of the device that is worn around the neck or near you. The other part of the device connects to the audio output of your TV and has the necessary cables to facilitate this. There is then a wireless broadcaster, a charging device (for the part that receives the wireless signal and gets either worn or placed near the listeners seating position - to which headphones plug in). Just let me know if you want it.
I got dad TV Ears. He's thrilled. He can't believe how quiet he can listen to headphones because it's so clear without any background noise. Mom is thrilled too. Thanks folks for your help.