Noisejunkie, at $580 or ~60% of your total outlay, you are grossly overspending on that Marantz. To reinforce what BSA is saying; to maximise audio performance (bang for your buck), your audio spend should be heavily biased towards the speakers.
So for instance, assuming you're looking at about $1000+ with AA shipping included, you should be looking at $700 - $750 for speakers and the balance on an AVR.
This AVR gives away little to the Marantz and is about what you should be spending:
Accessories4less | DENON AVR-X1100W 7.2 4K Receiver with Wi-Fi, Bluetooth, AirPlay. The difference in price goes half way towards paying for the Hsu sub (or similar), which will lighten the load on the AVR
and the speakers significantly.
I also recommend that you get monitors and sub initially. Then, if you really want towers, get them later on and move the monitors to surround duty.