If such a thing exists for the K engine what are you going to do about the ECU which is what actually controls how much you can 'rev up' to get the proposed power gains.
In both the short and long terms, it would be much cheaper to buy a Hyabusa although you won't get the quirky looks of the R
A Suzuki B-king has quite a bit more power but, as British magazine RiDE tested the B-King and K1200R together and found that despite the extra power of the B-King, the K1200R was faster accelerating and had a 9 mph (14 km/h) higher top speed, maybe more power isn't everything.
From my days of tuning BMC Minis and Ford Escorts (misspent youth) the big problem with hot cams and more revs, which doesn't always yield more power, is that the other components between your new power and the road surface will all need beefing up to take the strain. The K clutch comes to mind as the first thing to let fly, or perhaps the cam-chain sprocket which is integral with the crank on the K12 and is not replaceable or upgradeable.
If you really need more than160-odd bhp there are any number of tuning forms who will happily grind you a set of cams but don't forget the electronics...