I got a Uniqlo Packable Parka windshell. It’s 6 ounces, super breathable 30-denier polyester ripstop fabric, hood with drawstring, elastic cuffs and hem, full front zip, zippered hand pockets and a stuff sack for $40. https://www.uniqlo.com/us/en/men-pocketable-parka-419987COL69SMA004000.html
A mens XL is 24″ across the armpits, 29″ back length and 38″ from the center of the neck to the cuff. I would size up for layering. I think the breathability is the key thing here.

