It,s not BHP that kills the VQ motor when F/I , the motor has a week conrod , the fails when you try to run to much torque through the motor.
HKS say around a max of 360 lb/ft of torque (only a figure not a definite figure) on a STD motor.
A S/C conversion works best as it only enchances the STD output does not increase mid range torque a huge amount, where as a Turbo conversion alway gives a car a huge amount of midrange torue which will kill the STD con rods.
If HKS sold there S/C tuner kit a little cheaper and we can get around the LIVE mapping issues of the UK 276bhp that will be the way to go , I think around 400bhp flywheel and 340 ish lb/ft of torque would be pretty easily to tune the car for.
I am not keen either the Vortech ( to noisy) or the Procharger kits (inefficent) but the early and late HKS S/C work very well we find.
Mark