Have you tried the logger stuff? I think it is Tingley rain gear.

It is light, abrasion resistant pvc. You aren't going to win on a week like what we have coming up, but when I was a tree planter that is what I used. I liked it because of how light it is, and I would do a hoodie change at lunch time and that was more or less as good as I could get.

The neck is set up for a round hard-hat though, not a billed version.