You say you never use the fire, in which case, why replace it with a working fire?
Just block the fireplace up so that it is no longer drafty (that will be a real energy saver) and then put in one of those electric fires where you can switch the flames on and get the wood/coal burning effect, without any heat, and incorporating a fan heater for those very few days when an hour or so of extra heat would be nice.
When DD moved into her home she bought a cheap second hand electric flame effect fire as a temporary measure until she could decide what to do. 16 years on it is still there because it proved to be the perfect solution in itself.
You can then put a big tv, or whtever, on the wall above it..