Hey squid you really should let me tune that thing for ya!
but anyway. Like said cam can be done in car and to hit 300hp a cam really should be in the mod list. I would suggest if you an to keep the car for a while and want to mod to that power level get a tuner and start learning or make friends with a local who has a tuner. If you get your own, it is much easier and more forgiving to learn to tune on a lightly modded car then to wait and risk damaging the engine with a mistake in your tuning. I would start with your Maint first, then tuner and start learning, intake, headers, cam and springs, pulley drop. Too many people jump into dropping pulleys before they have a solid foundation for it. A header cam and properly tuned car with a big pulley will blow a car with a smaller pulley away if it doesn't have the supporting mods and has to drowned itself in fuel so it doesn't go Boom!