You have to decide whether you want meaningful heat (high efficiency) or a large viewing area.
A large room with cathedral ceiling looks silly with a smallish fireplace. There are some guillotine clean face fireplaces out there that have a large viewing area and provide a fair amount of 'radiant' heat. Which might be enough for your area.
Valcourt FP7 Antoinette is one and the
Valcourt FP1 Frontenac is even bigger. The glass door and screen raise up and disappear up above inside the fireplace and the glass is really easy to clean. Gorgeous fire. The Antoinette retails for about $4,500 and the Frontenac for about $7,200. Both on 8" chimney.
If you want high efficiency and something to heat your house with the
Valcourt FP10 Lafayette has some unique features. Huge single glass viewing area, high efficiency, 6" flue, blower included for about $3,000. For $600 you can get the heat management system on thermostat where it will push heat up to 50 ft away to another room depending where your comfort 'zone' (ie room) is.
Have fun in your shopping experience and remember the fireplace is the least expensive component of your project... Chimney, masonry, lumber etc... will bring the project up very quickly. So you need to make the right decision right off the bat since that sucker is not coming out anytime soon.
