My room is similar to yours: 15x16, 10 ft. ceiling and plaster walls. My gear was originally put together to fit a much larger room, but now it is waay overkill. Since my move 2 months ago, I've been experimenting with adding, subtracting and rearranging my speakers to determine what is just enough, and what is too much. If your room is totally dedicated to home theatre and doesn't double as a living room, I'd say a 46" screen is a good minimum size. My screen is 55", and I love it. With lights low, it dominates and envelopes, yet my couch is 8.5 ft. away. I say go for the gusto, just make sure you can sit far enough back (there are charts on this site comparing screen size, tv type and seating distance). Before I moved my room was 24x38, w/12' vaulted ceiling. I had 8 floorstanding Polk lsi & rti speakers, with a lsi center speaker, two HSU VTF-3 MK 2 subs, and a Klipsch RSW12, all driven by a Denon 5805 receiver. That room easily handled that much gear and power...it sounded great! Now I'm trying to find the right balance in a room almost half that size. It pains me to not use everything I have, but at this point, I have ruled out a 9.3 system. Definitely too much for the room. Now I'm deciding between 7.3 and 5.3, giving each configuration a hard listen. I'm keeping all three subs (overkill, but at least they can be blended into any set-up). It might take another month or so, but I'll let you know what I finally end up with. Even though your room is a bit smaller than mine, I believe you would be happy with at least a 5.1 arrangement. Hope this helps.
