You might consider putting in a better insert. I have an ~1,100 SF ranch with vaulted ceilings. Not well insulated at all. I have a Napoleon 1402 (has a fan) that heats my house, and does it well. I know folks aren't huge EPA fans, however this one is EPA certified and I'm really impressed. Burns wood substantially more efficiently than an old pot bellied stove I had in a garage. Due to my lack of terminology I'll call it a cadillac converter, but once the insert is hot it recirculates gasses from the wood, making it so efficient. Once it's going you can't even see any smoke leave the chimney, just a glimmer of heat.
Not 100% efficient, but I like it. Also is nice, I don't lose a substantial part of my tiny living room to a full blown stove. I got mine on craigslist for $800
http://www.woodlanddirect.com/Fireplace-...ASAAEgI0fPD_BwE