This little video series is pretty useful/informative. Start here:
https://www.youtube.com/watch?v=Sna5nGGzSDY&ab_channel=gooutdoorstvThe guy presenting founded a chain of big /out/ stores in the UK.
These videos made me want a Paramo, Gore Tex Pro or eVent jacket. In the end I went with a ME Lhotse (pic related) because I've tried loads on and this one feels pretty amazing. It gets fucking great reviews and I managed to find one that had been worn once for a few hours on ebay so got it fairly cheap.