I use the Pearl Izumi Gavia jacket (no longer made unfortunately). It's a soft shell and works great. I usually wear just a thin smart wool baselayer underneath and I'm comfortable probably 10F-35F. I'll wear something a little thicker below 10F. The coldest I've used this jacket is -17F and I've been fine with just a thicker baselayer. On the warm end, above 35-40F gets a little hot, but I usually just unzip the front a bit and I'm good. I don't know if PI makes something equivalent in their current lineup.

http://www.backcountry.com/pearl-izu...ia-jacket-mens

Paul