Hi, Don, and welcome.
Yes, this site is the best. I can't believe how selfless and non-judgemental the members are. I mostly lurk because I'm a noob with HA stuff, but am looking forward to the time I can return some of the help I've received.
You can just about read any of the marketing material for lighting control and come away thinking that it will work fine for you. We're building in SW FL, nothing as grandiose as your home (only 3,500sf), and wanted lighting control. At first, I thought Insteon would be great. Then I read about UPB. Hmmm, that would be great, too. Z-wave? Sure, that can do the job, if you believe the brochures. The recurring recommendation here is if your walls are open then hardwire. As my respect for the members here grew, I realized it was the right recommendation. My Centralite LiteJet panel was installed this week. I didn't do the whole house; tried to focus on the essentials. Figured I could supplement with UPB or other non-hardwired solution later. One of the difficult aspects of my build is we currently live on Long Island and can't be at the build as often as I'd like.
Good luck with your decisions and your build. Let us know what you decide.