All the AVRs mentioned are going to have nearly identical or identical sound. The only thing that really makes any one differ from another is the room correction software. IMO you should pick the one that has the room correction you like the best while still having the other features, warranty and price you want/like.
Klipsch RF-62II, RC-500, RS-400, SVS PC12+,
Def Tech SC8000
Harman Kardon AVR 1600
PS3, Apple TV, Sharp 70" Qattron