I think every jacket, and my winter over pants have the back zipper, I think its pretty standard on everything new. I've never used it though.
As far as the cooling effect of sweating and hot temps I've read a few articles and I try to spread the word to new younger riders, as the older ones stand firm with t-shirts and no helmet. But I've done some play testing, I'm very noticeably cooler with a mesh white jacket, than a t-shirt (and don't get burned!). Likewise cooler with a mesh jacket, than a solid one. No sun on my skin, good airflow, but not enough to blow ALL of the sweat away, so I still get cooled. The article I read, and what I experienced called it creating a micro climate in your jacket. Enough moisture remains so you don't dry out, and enough gets blown around for the sweat to create its cooling effect.
But anyhoo. I have seen quite a few of these pants in my searches. I'm just being picky. I too have seen Cycle Gears white mesh pants. I have their white mesh jacket. (It can stay relatively clean
) Sedici has a ok set, it zips up the ankle a bit, probably enough to get past boots or shoes.