Scottiemon:It would work, but I would strongly consider going with the 5C. The benefits to your HT will thank you! All Aperions are timbre matched, so you can mix and match.
Agreed, while you can mix the 4C with the 6Ts in a room of your size the 5C is probably going to be a better choice, unless you are sitting closer than 8-10 feet from the screen.
You should be fine with the 4Bs though as they work great as surrounds.
Jason Hicks
Aperion Audio Guru