I would say for your left/right surrounds definately consider Q's as most surround action comes from those channels. Many people really into 7 channel music, sometimes opt for bookshelfs for the rear channels. In my case I have 4 Qs8's and they work fine.
Axiom will never be mad at you, that is why they offer the guarantee for 30 days.
Sub placement is very tricky. How much have you really experimented with calibration and placement options? If you could post a pic of the room it might help us to give you options. The new Axiom 350 is supposed to be a great performer. A lot depends on your budget as well. One good option is that two subs are better than one, so you could put them on opposite walls, which would help flatten the low response in the room.
Also, if you order 5 or more items (including accessories) from Axiom, you get 5% off, plus if you order from the factory outlet, you get another 10%...
