Here is what I would do:
Denon AVR-4311: $1600
For a real THX kind of experience, go for
JTR Noesis 228HT x 3 for front stage: $3k
Combine that with some
Klipsch or
Hsu bookshelf speakers for surrounds, $550 or $350 shipped respectively. Use
these inexpensive but very good mounts on the surrounds, $25.
Get a pair of some large ported 15" subs:
Rythmik FV15,
Hsu VTF15h, or
Power Sound Audio XS30, which range from $2k to $2.5k per pair, depending on which you choose. The aforementioned Denon receiver has Audyssey's Sub EQ, so it makes setting up dual subs a cinch.
In a normal room, this system's performance will be on par with an Imax THX experience. Nothing Aperion offers could come close to touching it. This is a raw performance, high value, WAF nightmare. The ultimate for $7k outside of DIY.
HOWEVER, if you don't need that kind of dynamic range, and intend for a bit more modest volume music applications and would rather have a more aesthetically unobtrusive setup, I would look at
Ascend Sierras, KEF R series bookshelf speakers, or
Philharmonics for speakers. I would get bookshelf speakers and let the subs handle bass. Use the same Denon receiver mentioned above. Get two 12" subs or sealed 15"s, like
Hsu ULS-15s or
VTF3s, Rythmik
F12s or
F15s.