Not found anything which can cope with amount of sweat from running - walking yep (mostly), running no.
I work on the principle that skin is waterproof, and that the real problem is a combination of wet and cold, especially when teamed up with wind. I wear a windproof gilet, and that with a thermal l/s suits for virtually all winter (with gloves). If I was going somewhere remote where there would be a problem with rapid cooling, I'd take a small pack with waterproofs in. In summer it's always just shorts and t-shirt no matter how much rain.