I would recommend going with the 82" MU8000. There is no substitute for size. And this is coming from a very happy owner of a 65" X900e. For your main uses, the MU8000 will perform well.
My humble system:
Sony X900e; Sony UBP-X800; Pioneer Elite BDP-62FD universal blu-ray player; Denon 4300H AVR, Dual PSA S1801's; Monitor Audio Silver RX-6 mains, RX center, and RX surrounds; one pair NHT mini Atmos speakers; Home-built HTPC (Xeon E1230, 16gb RAM, Crucial M500 480gb SSD, GeForce 980Ti, Corsair CX600, CoolerMaster mini-ITX case)