Natoar :
You can use a K series chip with a H97 I have a MSI H97 Gaming 3 with a I5-4690K and it does support multiplier OC'ing but not Base clock
which was fine as mines happy at 40x100 4GHz on air
This seems extremely counter-intuitive. Purchasing a high-end 4690K cpu(~$250) just to throttle it on a (~$50) motherboard with no oc'ing capabilities.. If you're building a computer for your child, perhaps?
I thought it worth mentioning the opposite is also possible. An i5/i7 (non-K) for instance i5-4590 cpu on a Z97 mobo also has some overclocking potential. Its not a whole lot as the BCLK only has so much wiggle room, but a stock 3.3(3.7 turbo) GHz i5-4590 can be oc'd to ~4.0 GHz on proper cooling. If your buying new components, it definitely not the best as far as oc'ing potential, but if you have a non-k lying around, picking up a Z97/Z170A, saving up some $$ and then upgrading the processor to one with an unlocked multiplier is not a bad way to go. Personally, after a decade of unlocked amd/775 overclocking, I found the locked i5 provides awesome performance as far as single/multi-core applications and less stressful to boot. Going from an phenom x4 965 to 4590 was a ridiculous improvement, while providing all of the virtualization features with great longterm stability/reliability as a SOHO server. And on the next round of upgrades, it'll make a great htpc platform.
http://hwbot.org/benchmark/cpu_frequency/rankings?hardwareTypeId=processor_3635&cores=4#start=0#interval=20