For summer don't buy a black jacket, silver, grey or white is a lot cooler. Go for a mesh jacket with elbow and shoulder armour, one that has a zip out waterproof liner, some have two liners one waterproof and one quilted and waterproof. You can also get a gel scarf, you soak them over night in water and they swell up and slowly release water keeping you cool. They also do a vest but they can be pricey, I have one jacket that I can wear all year by just adding the liner and wearing a thin pure wool jumper.
Regards Martin.