At 1440p you're leaning a little more toward the GPU intensive side of the house, so you don't need the best CPU (7700K or other intel offerings) necessarily and a Ryzen would be just fine. However, 165Hz (I assume your display is OC'ing from 144) should drive you to want absolute max FPS, which means go Intel. If you're using gsync its not as critical as that should help with most risk of screen tearing that could result from you only having say 100-130 FPS when gaming on a 144Hz display, but to me, the more FPS the better. Seems you're investing in high end stuff here, and I'm also gaming on a 144Hz 2K Asus TN panel with a 1080ti, so personally I'd stay Intel. I'm actually on a 7800X clocked to 4.6GHz and my FPS are through the roof in everything at Ultra. Like 190FPS in BF4 for instance. In your shoes, if the 7700K is in your budget, I'd go that route over Ryzen. I personally own a Ryzen build as well but use it for work every day and it does great but no matter how much people want to love Ryzen it will not provide as high of FPS as Intel offerings, though pretty close.
The 7700K isn't gonna cool any worse than any other current Intel CPUs. Even if you jump to a Broadwell-E, which is soldered, you're adding 2 cores which add more heat right out of the gate. If you overclock, just do your best to keep voltage as low as possible on the clock you want, be sure to invest in a good cooler (that Kraken is fine) and feed those radiator fans cool air and you'll be fine.