Both Windows 10 and Windows 11 are good operating systems and will work well on your new rig. However, Windows 11 has some new features and improvements over Windows 10, such as a redesigned Start menu, better support for multiple monitors, and improved performance and security features.
If you don't mind trying new things and want to take advantage of the latest features, you may want to consider installing Windows 11. Just make sure to check if your hardware meets the minimum system requirements before upgrading.
On the other hand, if you want to stick with a more familiar and stable operating system, you may want to stick with Windows 10. It's a reliable and proven operating system that will work well with your hardware.
Ultimately, the decision comes down to your personal preference and needs. If you're unsure, you can always try both and see which one you prefer.