Which CPU i7 from 5930K, 4970K or 6700K?

Hello,
having to assemble a new PC for Cubase 8.5 and several Kontakt libraries + EastWest Play (for MIDI mockup) I do not know which CPU choose to build it… I’m looking for a i7 that can handle a large number of virtual instruments and kontakt libraries and do not know which one to choose between 5930K, 4970K or 6700K.
Excluding Xeon course for economic reasons, I would be oriented to 5930K that has a good quality/price ratio but do not know if I make the right choice, since it is a now old system.
Does anyone have experience with this CPU on motheboard X99 or do you recommend the newest i7 6700 chipset Z170?

Maybe wait for Broadwell-E which is supposed to launch at Computex at the end of the month.
http://www.pcgamer.com/first-benchmarks-of-intels-broadwell-e-core-i7-6950x-appear/

Thanks Tracker, looks very interesting! But I think his price will be higher…
Also I have to buy soon because my current workstation is out of order.
For this reason I remain undecided on the above cpu.

I am quite happy with the 5960 (running on an Asus X99 Deluxe). Fast and stable OC @ 4.4 ghz

My new overclocked 6700k build can do 1024 voices using Halion Sonic SE (64 instrument tracks with 16 note chords) with a buffer of 64 samples @ 44.1 kHz. Asio Guard is on, no tracks rec ready.

That’s about as powerful as an overclocked 6-core 5820k I tested a while ago.

YMMV, Kontakt is different form Halio Sonic, of course.

im using i7 5820K and runs extremely well. I think its more how you use cubase rather than what CPU to get. if your using tonnes of tracks and MIDI and plugins your doing something wrong sonically, LESS IS MORE!