how would someone go about modifying a Pontiac grand am gt?

hello! Ik it seems crazy to some people, but my dream car is a heavily modified pontiac grand am gt. My mother has one now, it runs great at 252k miles but needs a new front bumper and fenders. Even if I cant keep this specific car, I still want a GAGT. I don't know everything about cars yet, but I'm also not completely clueless, I can tell the difference between a alternator and a turbo. From what I know, my first modifications should be things like suspension, braking, steering, and so on. but Id like some advice on what I should expect. Will I have to swap the engine or will the stock 3400 handle 200+ hp modifications? would the trans have to be swapped? where would I go about finding someone that can make custom GAGT parts? would I be able to swap to a AWD drivetrain? I appreciate any help, and I dont care how expensive these modifications might be.