The more I research it and pursue various possibilities, the more I accept that going for "waterproof" and "breathable" always involves a heavy tradeoff one against the other, with neither winning out. Currently, I'm wearing a Sugoi Hydrolite jacket for light waterproofing with moderate breathability (while being very small and light) and packing a tiny plastic raincoat in case of genuine downpours when I really don't want to get soaked. Although I've got a pair of Sugoi Majik shell pants for more thorough waterproofing in non-emergency situations.