I have a Thinkpad T480 and I’m very happy with it. I paid about $250 (~£190) for mine. It came with 16 GB RAM, but is upgradable to 32 GB. The one I bought came with a 128 GB SSD, but I swapped it out for a 1 TB drive which added another $100 (~£76) to my initial investment. This model originally came with Windows 10 and most on the market will come with it, but can be updated to 11 if desired.
I personally have not used Win11 since they made some changes I don’t like, so I can’t really give you advice on that aspect.