Id go with good faith and a fire extinguisher
300 bhp N/A sounds like a dream. How will you achieve this? I recon youll need about 70bhp of nos on a very highly modded car. Expect a catestrophic engine failure soon. Nos is a great thing but only when its set up well. I think a large shot of nos will destroy the engine. It needs to be a forged engine to take the abuse.
why are you aiming for 300bhp? 230bhp would be very quick and can be achieved with little engine risk.
300bhp is going to cost alot to achieve.