Whole Home Audio and TV room Advice

Hello and thank you in advance for anyone who provides input!

I have a home that I would like to fully outfit with home audio, a TV area with 7.1 (LG G4 planned(?), and two bedrooms with 5.1. I used the free Crutchfield design services to help me with a starting point to see what they would specify (link: https://drive.google.com/file/d/1ufbT0oHp4iNGSY8j1M8hcoi7QK6b5F4K/view?usp=drivesdk). I have not done any big AV projects like this, so in addition to my research, I’m asking the wonderful people of Reddit for their advice.

A few of my basic questions are: 1) Are there brands or systems out there that are more bang for the buck? 2) at this price level is it worth spending some more money to level up with speaker quality? 3) the home is built and I will be fishing all the wires myself. I’m novice-ly handy and feel that running wire through the attic and walls should be ok (albeit frustrating and requiring patience I assume). Is there anything I need to think about when ordering that would help me in the future? Perhaps run extra wiring to places that I might expand to?

Again, any and all help/tips would be a huge help!

Budget and location: budget is about $20kish. I had a consultation with Crutchfield and they came up with about $15k (but this does not include (3) TVs that I will need.

How the gear will be used: this will be for whole home audio, a TV room with 7.1 (LG G4 planned(?), and (2) bedrooms with 5.1. Will be streaming video, music, and a vinyl player.

New or used: I prefer new to keep things simpler/cleaner and warrantied.

Past gear experience: in the past I have had whole home audio with denon HEOS as a base and one tv room with 5.1. For this I did not do any purchasing or installation on my own.

Thank you for quite literally any help!