Consider this
That cpu you got is not much of a bottleneck. From what Linus from Tech Tips has to say, your gonna get a 10 fps in your games with that skylake . Wish i could give you the link, just look through his channel.
I'd say w8 for october. There is a 50% chance , maybe more to see a release from AMD Zen. The cpu that you have is fine, and so is mine. I have less than you, but it's enough, i also do photoshop and adobe premiere. Your gonna get a little bit more from that 6600k . Benchmarks show one thing, real life is less exciting.
Save your money. Don't be in a rush.
P.S. I was a sceptic, on the ssd. Not any more. So if you wanna see real life speed in your pc. Go with a ssd. You will not regret it.
There will be a huge surprise with amd zen, and even if it';s gonna be october ,or maybe late december, even next year 2017 february. You are good with that graphics card and cpu for gaming.
Think about it.... if you really wanted, or afforded 4k ultra high gaming , you would have got a different computer. So your gaming 1080 and with new cpu & ram , your gonna gain 10 fps more at your 1080 gaming.
Think about it. Save your money.