Caporegime
Looking good! RX6's will sound sweet. The x3000 does sound nice, or if you can find an avr3312, that would also sound nice.
For all the people wall mounting....(correct me if i'm wrong) but TV's ideally should be eye level. The centre of the TV to be precise should be level with your eyes!
Ergonomically speaking, the top line of the screen should be as close to eye level as possible when sitting down.