Need some decent 12 gauge wire to hook it all up that sounds almost identical to the best wire in the world? Try some electric wire from Home Depot - yes, the same stuff that's hooked to your light switches. Actually, your light switches are probably using 14 gauge wire. 12 gauge electrical wire is rated to 1920 watts of power - think that's enough?
Seriously, if anyone here can determine in blind tests the difference between 12 gauge electrical wire and the top of the line Monster, Belden, or Straight Wire then I would be very, very surprised. Likewise, the difference between blister pack audio interconnect cables and top dollar interconnects.
For your A/V receiver needs...
How many zones of audio do you plan to run off the receiver? Just one, or do you have multiple rooms you are planning to set up?
If your goal is just to have one room that sounds really, really good, then I would take a step back and take a long hard look at buying a separate A/V preamp and a good 5 - 7 channel amplifier. I got the Yamaha RX-Z1 and am very happy with it, but if I had more money I think I would have gone separates.
Otherwise, in my opinion, you can't go wrong with whichever you choose. Yamaha has an excellent product, as does Denon. They both sound great and work well. Neither, that I have heard of, have major reliability issues that people are complaining about. So, whichever you choose, is fine and you will be happy with.
But, be ready for upgraditis when you start looking at separates.