I think I have narrowed this down to a few choices.

ML Electromotion R
GoldenEar HTR7000
TruAudio REV8-LCR.1
Beale Street something or other (ADI sells their house brand...W-Box...which uses the same Sonic Vortex technology and they are cheap enough I could throw a pair in and move them to the kids' bedroom if they were not up to snuff enough for the surround system...mainly I am curious how well the bass response is compared to others)

If I could, I would roll with some ML Vanquish or some of the Silver or Gold Triad models...or even the Totem tribe in-ceiling. But that kind of $$ can wait until our next home which will have a dedicated space for the theater. This is a "get me by until then" system, so budget constraints dictate a lower cost speaker.

I did find a pair of the Bostons that were mentioned earlier. We have a set collecting dust in the warehouse. I could probably walk away with them for nothing honestly. If we had a 3rd, I would go for it. Maybe a search of the web of the whole wide world is in order. That would open my budget up for better something else. :)