Your Free Thinker has a Gore Pro membrane, which is one of the most breathable shell materials on the market. Black Diamond's most breathable shell, the Sharp End, is made out of the same membrane, and slightly denser (ie. less breathable) face fabric. They do carry the Dawn Patrol soft shell, but it's brushed, so while it's more breathable, in a way, it's still warmer. The Alpine Start and Cirque are lighter, but are cut & designed more for climbing (I could see the Cirque being difficult to layer under).
Whatever kind of shell you get, I highly recommend layering it over your mid-layer. Any insulation layer needs to be closer in to your body where it can capture the warm air in the insulation. Any shell you put on under it is going to keep your body heat from emanating unless it's a super minimal summer softshell like the OR Ferrosi.
I have the Arc'teryx Gamma LT and the Dynafit Mercury, and there's definitely a trade off between breathe & wind protection, and the right balance between the two is probably going to be personal. But the one way to cool down that comes without any sort of compromise is to drop a little weight out of your insulation.