Very nice build. I really wish I had the budget for my build to add one of the RTX cards, they look beautiful and they're beasts.
I feel like they should have held off until around mid- to late- 2019 to release RTX and maybe they could have made another generation of GTX cards.
This thing is pretty expensive. Guess that your job is so much easier now. The only thing I'd change, only because of personal preference, is the mouse. For less than that, I could get a nice wired gaming mouse, like a Razer DeathAdder, because there's more of a delay for wireless connection than than it being wired. I'm no expert, but this is must be one beast of a computer.