Pretty good build. I prefer Asus mobos over Gigabyte but its just more of a brand thing. Unless you are planning to run SLI, you shouldn't need a 750W psu so you can get a cheaper one.
I'd personally get Windows 10 from Kinguin since its basically more than half off there
https://www.kinguin.net/category/19429/windows-10-professional-oem-key/
Here is a video about the keys themselves for a reputable dude
https://www.youtube.com/watch?v=yXTqz3Fd28M
I personally never bought keys from that site myself cause one of the benefits for being a student in IT in the past is that we get free windows licenses through Microsoft's DreamSpark but they seem to be pretty legit. Use at your own risk tho.
PC Specs: CPU: 7800X3D || GPU: Strix 4090 || RAM: 32GB DDR5 6000 || Main SSD: WD 2TB SN850
