down = not that great if wet. You use em under a hardshell if it’s raining.
If you want one jacket that is shower proof and snug, a pile based montane, buffalo or snugpak jacket would be better.
Buffalo are great and they are made in Sheffield. They are the original pile “soft-shell” system… They do a range suited to cycling.
Pile jackets act a bit like wetsuits, so a lot of wearers will use them without hardshells….as the reasoning goes they are more breathable than hardshells….if you get sweaty you potentially get cold….so they reduce that whilst keeping you warm when wet……the “wet and warm” school of thought.
Lots of squaddies use them.
Short version – are you sure you want down? Depending on the kind of walking, you may get sweaty (down doesn’t ‘breathe’ as well as synthetics, apparently).