For an ATMOS system they do recommend direct firing. Specially with the QS8 firing up wards and the rear ATMOS firing downward on it.
NicBuol has done great research on this and very informative. He has a awesome setup you can probably see most on the posts on his HT here.

I would suggest going with atleast EP500 duals. I have EP350 and in a room 11.5 x .15.5 x 8 and one doesn't cut it. I am even considering three or four.


Anthem MRX520
M5HPv4
VP160HPv4
QS10v4