I love this jacket: Amazon.com : Louis Garneau 2013 Men's Electra 2 Cycling Jacket - 1030116 (Bright Yellow - L) : Cold Weather Cycling Jackets : Clothing

It converts to a vest pretty easily. It's heavy enough but not too heavy. For colder days you can wear something heavier underneath. It has good vents for warmer days. Very versatile. I'm sure it would work well for running too.