Hi Eskild,
Welcome to the new Rennsport Forums,....its great to have your participation here! We'll try to offer useful & constructive assistance when and where we can.
I like your performance-enhancement "recipe", however I'd offer that 10.5:1 is too high for pump gas with single ignition. Even in you climate and
98RON fuels, I'd keep this under 10:1 so you have room for decent ignition timing. This is why Porsche never went over 9.8:1 on single-ignition street cars,...
If you really want 10.5:1, you will need to machine your heads for the lower plugs and install a twin-plug distributor.
We do indeed have JE make pistons to our specification since their regular 911 pistons have too much top ring land clearance. This allows the pistons to rock around the pin axis more at TDC, thus increasing ring and piston wear. Makes more noise and smoke, too. You can e-mail me directly to discuss and order.
Power-wise, a properly built engine like this has MUCH better throttle response (due to PMO's) and should make around 225-230 BHP with a 27-30 Nm bump in torque.