Others will probably answer better or differently but here is my take and what we did.
First, you are correct; Directv HD eliminates all the inexpensive carry outs. The roof top is about $1800 and rooftops often get blocked by trees.
I switched to DISH as the $400 carryouts get HD, no roof mounting required and you can move it around to find a clear spot if need be.
I chose the Winegard Pathway X2 with a plain jane 211Z sat box. The Pathway lets you choose either DISHs eastern arc or western arc which can be a big deal with trees. I could not be happier with the Pathway.
I feed our outside tv with a wireless HDMI transmitter. But with as many tvs as you have I would go with a Hopper and however many wireless Genies you want at $7 a month. No cables.
I have found DISH much more RV friendly than Directv.