Since you sit pretty far from the TV, in a case like that it is always better to go for the bigger TV. If you are ready to go bigger than 65", the 70" KU6300 would be a good choice since it can be found at around $1500. If you decide to stay in the 65 inch, then you should go with the Vizio M Series 65".
That being said, the Vizio and Samsung are good if you'll be sitting in mostly in front of the TV. If your seating area is wide with some positions being of center, you should look for an IPS TV with better viewing angle like the Sony XBR65X850D.