Im looking at spending around £100 more for the 580 4gb compared to a 1660 6gb
https://uk.webuy.com/product-detail?id=sgraamdradrx5804gb&categoryName=pci-express-graphics-cards&superCatName=computing&title=amd-radeon-rx-580-4gb&referredFrom=search
https://uk.webuy.com/product-detail?id=sgranvi1660gtx6gb&categoryName=pci-express-graphics-cards&superCatName=computing&title=nvidia-geforce-gtx-1660-6gb-gddr5&referredFrom=search