It is a known fact today that not all processors are fused equal. Some can 'clock better than others, and if you happen to find a gem you can count yourself lucky having won the silicon lottery.
Or, you can simply go to the Silicon Lottery and buy exactly what you want! Siliconlottery.com is a Texas based online store that sells CPUs by the frequency bin. The product range is quite minimal: Core i7 5820K from 4.4 GHz to 4.7 GHz, Core i7 5960X from 4.5 GHz to 4.7 GHz, and Skylake offerings in the form of the Core i5 6600K and the Core i7 6700K. A Core i5 6600K rated for 4.8GHz is priced USD $300, which seems like a reasonable price. The Core i7 6700K is not in stock yet, but is due September 10th.
If you're looking for a decent overclockable Skylake processor and you don't want to bother testing a couple yourself, perhaps this is a good opportunity. In case you're looking for aid with delid, there's a USD $50 delid service available too!
Check out Siliconlottery.com for more information.