Pc build advice

Hey everyone, I’ve got a bit of money to splurge and have done some research just looking for some critique or recommendations before I continue buying.

Build so far: CPU Ryzen 9 9800X3D (planning to upgrade next Micro Center trip) GPU MSI RTX 5090 Gaming Trio Motherboard ASUS ROG Strix X870E Gaming WiFi RAM G.Skill Trident Z (2×16GB) 6000MT/s CL30-38-38-96 CPU Cooler ASUS ROG LC III Case NZXT H9 Flow (2025) Case Fans   3× Lian Li TL Infinity Fans   3× Lian Li TL Infinity LCD Fans   5× Lian Li TL Infinity Reverse Blade Fans PSU Corsair HX1200i

I know this is a lot, so thanks for taking the time to read. Any feedback on compatibility, performance balance, or better part choices is appreciated!

Also where should I get my windows key?