Windows 10 Enterprise LTSC 2021 is packed with features like UEFI-ready and the Diagnostics and Recovery Toolset, as well as a pre-installed servicing stack and cumulative updates. The instructions for creating a bootable USB with Rufus are clear and easy to follow.
You can always look for the activation keys on Reddit windows keys where people sell them cheaper than you can get them in a shop. Just be careful and choose a reputable reseller to buy from.
I've upgraded to Windows 10 a few months ago and it's way better than Windows 7 I have been using so far.