Skylake, Haswell-E or Broadwell-E?

[titaniumx3]

Sorry if this has been discussed to death already, but need some expert advice.

Looking to upgrade soon and was wondering what would be best. Current system is:

i7 2700K @ 4.6ghz
Asus Z68 Mobo
16GB RAM
980Ti
SATA SSDs and HDDs
Corsair TX650 PSU
Antec 300 Case

Everything is working fine, but its just getting a bit boring now, nothing to tinker with and I'm pretty sure something will give out soon. Case and PSU are 7 years old, CPU and Mobo are 4 years old. I think some of the case fans are starting to die as they are making a weird buzzing sound. Anyway, point is I want to upgrade soon and would like to build a completely new system, with only graphics card and SSD/HDD carried over.

I'm currently looking at the 6700K and 5820K, but was wondering what is better value? I know 5820K is cheaper, but offset by higher motherboard cost. Also I can't see any benchmarks that compare them clock for clock. Also what sort of overclock should I expect from both processors? Finally, with Broadwell-E close to release, should I wait for that? Ideally, I would like Skylake-E but that is too far away. Looking for gaming performance mostly, but like having a balanced system with good versatility and future proofing.

I intend to stick to a premium air cooler. Is this a bad idea for these CPUs? Not sold on these AIO water coolers and not prepared to go for a proper WC setup.

Finally, I also fully intend on getting a M2 formfactor PCI-E NVme SSD. Which platform would be better for this?

Would really appreciate some advice!

 

[titaniumx3]

I reckon, I'll wait for broadwell-e in that case then. I think it's mostly down to wanting a new motherboard and less about the CPU. I will also need to upgrade to Win 10 soon and thought a new system would coincide nicely with this.