A couple of points, one your room is very large, and two you should narrow down which speakers you are going to go with.
The Whispers employ bass amps which does take a lot of work off the main amps so do some of their new models.
I would settle on the speakers first. I would also consider for a similar price point to the Whispers the Kef Blades with a good JL sub as another awesome package.
The Legacy's speakers have been shown with great sound with the CODA electronics.
I would recommend the Chord stuff which is unbelievable sounding and they make very powerful monoblock amps.