Tactfully suggest returning in-ceiling speakers for towers, bookshelfs, or at least in-walls. I hate to be critical, especially since this is outside of the thread's scope, but in-ceiling speakers are just about the worst kind you can get. As far as those subwoofers you listed, they are all underpowered for a space of that size. I guess you are needing to to keep them small for aesthetic reasons. You might try the Klipsch RW12d, it isn't much bigger than the Lava sub but it ought to have a bit more output. If you can accommodate a larger sub, I would look at the aforementioned Hsu VTF15h or Epik Empire. If you can get a Rythmik FV15HP that would be even better. But pairing a Rythmik, Hsu, or Epik sub with an in-ceiling speaker system is like putting a fine red wine sauce on a McDonald's hamburger patty, it's just too awful to think about. By the way, I don't think in-ceiling speakers are bad for the surround channels, although they wouldn't be my first choice for that role either, but for a front stage, they are dreadful.