If it were me, now I love a good fire and burn often, I'd put in a fireplace insert. Vermont castings offers a fireplace insert that slips into your fireplace, you might have to remove part of your damper but it uses a SAFE chimney insert. It also sticks our into the room slightly naturally emitting more heat. They also have heat exchangers and automatic temp switches for the blowers. They claim to heat a fair amount of space, i believe 2k sqft with a burn time of up to 12 hours. They also have auto air control to control the burn. They are like a nice firebox only look exactly like a fireplace with a nice view area. If I weren't selling my house I'd have one right now, I got a quote of around $3k installed a couple of years ago. I wish I had done it, I would easily have saved that much in propane costs! When I sell my house I am searching for a new old house, I've already decided if I find one without a fireplace it must have a place fro me to add a fireplace - I'm adding a Vermont casting insert!
Kurt