Build the system just like you would at home. Huge Audiophile you say. I'm the same.
I used a Cradlepoint MBR router with a verizon data stick. For audio, attached to that is a NAS drive that stores 20,000 songs in apple lossless that plays thru 2 separate Sonos Connects so I can play all my music controlled by my phone sitting in my lawn chair. Inside I have a Marantz AV receiver, Dish Hopper, and 5 6" Klipsch in ceiling speakers and a Velodyne Mini Vee sub. Amazing sound quality. Most quality AV receivers have more than one HDMI outputs so 1 to your main tv and 1 to your bedroom tv.
Outside I have a Sonos Connect as my source that runs thru a Bryston B100 integrated to a pair of Tera outdoor speakers that I hang on the side of the coach. I also have an input for audio from my outside tv.
SQ is incredible.