Not really concerned with "breathable" much at all. I would love it if it was waterproof enough that even after an hour plus in heavy rain little to no water would get through. I ride easy enough on my commute I do not sweat much if any.
My one concern though, my jacket is bright yellow and I would love it if the coating would not change that much.
I've used Plastidip, the stuff that you coat tool handles with ... as a recoating for my Cordura Bags.
when the mill coating wore off on the inside..
I suspect you can find it in yellow and then paint it on the outside.
I myself went over to a thickly PVC coated fabric made into a Rain Cape.
the breathability is zero.. but as it's not clinging to my body, there is sufficient ventilation
coming in from underneath..
Grundens of Sweden.. makers of the foul weather gear fishermen wear at sea.
Rivendale Bike got them to make the capes they sell .. using their seam welding production machinery.
Grundens themselves make jackets.. and Bib overalls
http://www.grundens.com/index.php?op...d=18&Itemid=80