In the end I settled on the Asus TUF Gaming B850 plus WIFI motherboard, and 32GB Corsair Vengeance DDR5 6000 CL30 RAM that was on the support list for the board.
The CPU has also arrived so I looked into cooling options and found a AM4 > AM5 upgrade kit for my Cooler Master Hyper 2012 EVO black edition. All you get though are four large metal stand off screws and four nuts, and no instructions, so does anyone know how to use them? I was expecting a back plate or something, the Cooler Master website was no help either I was expecting at least a diagram or something.