I went down a similar rabbit hole as you last year and ended up going the route of layering so I can adjust according to warmth. This is typically my setup on cooler days:

Baselayer - Patagonia Capilene Air Crew - great at breathing but also keeping you warm. T-shirt or shirt of choice Patagonia Down Sweater - VERY light coat, with down feathers it keeps me very warm, but once again breathes well to keep from overheating.

If it is bitter cold due to wind, throw on a windbreaker of some sort over this setup.

It has served me well and has been my go to since.