Moving, new DirecTV Ready 4K TV - DirecTV

We are moving and have purchased a new Sony DirecTV Ready 4K TV. I have NOT yet called DirecTV to schedule the move but am hoping for some info here before I commit to continuing with DirecTV.

Here is what we have:
DirecTV H44-200 (will be connected to new Sony 4K TV listed below)
DirecTV C51-500 x2 (will be connected to two existing 1080p flat panel tv's)
Sony XBR-65X850D (DirecTV Ready 4K)
Yamaha RX-A3050 (capable of 4K upscaling)
AT&T Business Internet

House we are moving into already has a DirecTV dish.

I will have the internet hardwired into all components (other components not listed) and TV via Cat6 ethernet cables from an 8-port Gigabit switch.

1) Is our existing DirecTV equipment compatible with our new Sony 4K capable TV?
2) We have the overpriced DirecTV Xtra package, what if I don't want to spend the extra $$ for the overpriced Ultimate package?
3) What other issues should we be aware of with this new 4K tech?