Hello and welcome to justanswer.com my name is XXXXX XXXXX I'm here to help you with your TV problem.
Yes unfortunately if your TV doesn't have these plugs then it makes things difficult.
You have found the only option but your wireless headphones need to be able to accept a RCA line input. If so then the plugs you need to attach to on the back of the SA box are what I'm sure you have already seen.
What wireless headphones are you using please and when you're not happy with the results can you elaborate?