I was thinking of a new 4 bay enclosure, RAID10, probably 4x16TB drives. Not going to be cheap but would see me covered for a few years I would hope.

From reviews, it would seem this is a good option.

https://www.synology.com/en-us/products/DS920+

Fast, decent reviews and easy to set up, operate and so on. Will only ever be used by my own family.

Any other suggestions based on experience or other options I could consider?

Looking at £2k for that one with drives which is not ideal but if I have to then so be it.