you can't just add air without bringing-in more fuel
Anything for less than 7-8psi, you should able to leave your engine component untouch (but still need add fuel)
Are you going to have intercooler ?
How are you going to change your fuel ? Stand-alone ? Piggy-back ?
If your head gasket is healthy, no change is necessary.
Look like you need to more reserach before you Supercharge your car.
Or play good money and let someone else solve your headacne