Perhaps a rain resistant cycling vest?
http://www.performancebike.com/bikes//Product_10052_10551_1009601_-1___Which I'd match up with a rain resistant ball cap (I wear glasses) and polypro glove liners.
Vaseline on feet and front of thighs?
Agree with lots of body glide for chaff areas (I often carry a "sample" for emergencies)...
- Nipples?.. Hope body glide is enough.. perhaps pre-tape?
Or spray entire outfit with Scotchguard (after you dress)... ; p
- The last time I ran in the rain it was a 24-hour race, so full body armour was in order....
Have fun...