the best advice is just to follow the steps Cobb and Mountune have created for you. Drop-in filter, Accessport with Mountune tune, and RMM. Start there and see how you like the car. So many modifications are way more than what the car needs and probably close to pushing the car into an area where reliability, warranty concerns, and driveability start to be affected. I have built too many cars that ended up down that path. The ST comes to life with an Accessport, filter, and lower/rear motor mount. It is a minor investment with huge returns. Don't waste your money on monster intercoolers until your data gathering on the Accessport indicates the need. Don't waste money on braces claiming to improve all sorts of things on the car. Your tires will give up grip way before you generate enough force to deform the chassis and suspension. Don't waste money on a cat-back, unless you want sound and realize there is very little performance change. Don't buy a questionable tune because it is cheap and end up with the car on a flatbed heading to get a new engine. Research, pick your modifications carefully, and enjoy the car. Don't get in a hurry to build a dyne sheet monster to be popular on the internet. Enjoy the process of modifying the car over time. I had huge plans for my ST when I got it and quickly realized a few minor tweaks was all that was needed to make the car perfect for me. It isn't popular on Facebook or at car shows or putting down FTD every weekend or throwing down big dyno numbers. It instead is the right balance of performance for what I want in a car that I drive 90% of the time.
I will add though that for some in extremely hot environs (especially during the middle of summer), the bigger aftermarket IC might be a necessity, even without/before any data logging info.
Also, for me at least, the aftermarket wheels/tires ARE a necessity, even if they are not drastically lighter than stock (like most on here say they MUST BE in order to be of any benefit at all), since I just cannot stand the looks/aesthetics of the factory wheels, and the 'rubber band' profile tires mounted on them.