I go with The Packa as my rain top as it also triples as my pack cover and pillow. It is very light weight with pit zips. If I want to use my Packa as a pack cover only, I tuck the sleeves behind my back within the pack area. http://www.thepacka.com/
And, I use Marmot rain paints for bottom protection. However, if it is warm enough, I don't put on the rain pants. I use the rain pants mostly for late Fall, winter, and early Spring.
Keep in mind the fundamental purpose of rain gear is not to keep you dry but to keep you warm. Hypothermia being the primary issue of concern in inclement weather should be keeping the effects of wind and related driving rain, ice pellets, snow, or sleet to a minimum. Intended altitude and other factors can come into play with that decision as well.