Out of curiosity, what CPU are you upgrading from? There's not a huge performance difference between Ivy Bridge and the newer Kaby Lake CPUs. If you're really prepared to shell out significant money to get on the latest platform then that's fine, that i5 7600K is a good CPU, but it's a fair bit of money for what might be a fairly minimal performance improvement... depending on your current CPU.
Also, Ryzen launches in a early March. If you're looking at CPU + Motherboard + RAM anyway, then it's probably worth waiting to see whether the price/performance landscape shifts after launch.