Jack888 wroteDefo fancy going the 996 route, Surely finding a 996sps engine would be a task and a half??
You just build one.
Start with an ST4S motor (996cc). The swingarm will bolt to the cases and you can sleeve the original motor mounts in the engine or just enlarge the frame holes a touch and use the larger, stronger ones. SPS or replica cams will give you most of what you want (or allow you to do build the motor in stages if you wish). Exhaust will have to be tweaked a bit unless you swap the ST heads for the 996 superbike heads. 996 heads aren't expensive and allow you to bolt on any 851/888 exhaust you like, so it makes sense to do that.
The ST4S bottom end will have a heavier crank and stuff, but if the day comes when you decide to tackle that, you can get some high compression pistons and take the opportunity to lighten and rebalance the crank.
If you've bought an entire ST4S donor bike, you can use the wiring harness, throttle bodies, and 5.9M ECU, which can be reprogrammed much easier and more effectively than the chips for the P8 (or swapped for a plug-and-play Microtec M197). Then you can even add a quickshifter. 😉
How fast do you want to spend?