^ As someone who recently began spending way more time at the track, I think the above advice is the best. Just get your brakes bled, and be prepared to learn a whole lot about driving technique.
Once you've decided you're going to do this regularly, shell out for a good helmet first! This is something that is going to be very noticeable right away, and unless you plan to go through helmets often, you'll have to live with it for years to come.
As you begin pushing the car more, you'll get a better sense of what needs to be modified. You've obviously done some research, and you've got a good idea of what will probably need changing first. Good brake fluid, pads and stainless steel lines will be more than enough for most track days. Your tire/wheel choice will be tied together since you'll need to decide square/staggered fitment etc. I'd suggest that this can wait; feel how MDM mode works, play without traction control to feel out the car, and from there, your driving style will give you a better idea of which way to go.