Hmm, since your looking for a fireplace that can be shown alongside a play list, that definitely seems to be something an actual visualization needs to be created to accomplish, though there may be other ways that are available. To accomplish such a visualization, you probably need real-time footage of a fireplace to make it look decent, and I doubt anyone would want to create some kind of animated fireplace, which would look like crap anyways. I never created a visualization, so I'm not sure if video footage can be incorporated, or at least set up to just play on demand.
There's a thread on the xbmc forum of someone that actually created a visualization of flames to appear like a fireplace, but its just mainly animated flames going about the screen, which i doubt is what your looking for.
If you want to check it out, here's the thread link -->
XBMC forum flames link . If you scroll down the thread there's a link to download the visualization, which you could extract and copy to your xbmc's visualization folder to see how it looks.
If no one else has a solution, here's a link to a DVD of a fireplace that looks pretty good, though you won't be able to play your music with the footage, well at least I don't think you can. -->
DVD Fireplace Link