consider mesh neither leather nor ballistic fabric is cool
Mesh is yet still excellent protection and armor.
It's easy to make warmer, $60 liner and whatever rain jacket you choose- it's impossible to make the others cooler - easy to make the mesh warmer.
I wear a JR mesh jacket with armour and love it. Ride from 8 degrees with the liner up to about 30 when like today - it's a short sleeve shirt.
Great armour you don't even feel.
The $60 liner makes it warmer and windproof.
Have TWO ballistic touring jackets ( one a 3 pc set ) - never worn them. ( the JR XL set is for sale on here )
Have been wearing kevlar sliders but just ordered Olympia Recon 3 Mesh Pants which are convertible ( there is a thread around. )
The Kevlars are flexible and comfortable but damn are they warm. Nice thing is they can pull over boots.
They don't look arrmoured but are.
The Recon supposedly provided excellent protection while much cooler and they convert to shorts which is something I wanted.
http://www.revzilla.com/motorcycle/olympia-recon-3-mesh-pants
There is a ton of gear here
http://www.revzilla.com/search?query=recon+3&x=0&y=0
with good videos and explanations.
Incredible what's available and getting better every year.