I'm really not trying to be a killjoy mind you, that is a seriously gorgeous set-up you have planned out... & you obviously spent some serious time and effort in designing it. It's just that I went about it the same way, designing my HT in such a way that I thought would look elegant while utilizing my space efficiently. And the space that I incorporated my subwoofer into the fray (built right into the wall below my TV) literally sucked the performance right out of my poor EP800!
So I just thought I'd give you a bit of a heads up about finalizing a design before you've tried out the hardware to make sure it's going to work. Which admittedly is very tricky indeed as sounds are going to change everytime you do something else to the room (like lay carpet, build the columns, enclose the structures on either side of the screen, etc...). So it becomes a real catch 22, you won't know what it's going to sound like until you're all done... but in a project such as yours, once it's done it's not so easy to alter.
The one thing you do have on your side however is Axioms excellent trial program. Simply order the speakers of your choosing, try them out in the areas you would like them to be placed, and try em out. If the sound isn't to your liking, and you don't want to move things around to try to tweak their performance to match your desired expectations, then you can return them within 30 days of purchase and try something else if that's what you desire.
But here's to everything sounding fantastic in all the locations you have picked out for the speakers at this time. I sincerely hope all goes well for you my man! That is one fine looking design.
