I don't think you should spend money on rotors unless your stock rotors are worn.
If you're going to leave the pads on for dual use, I guess Ferodo is best. Even better, keep the stock pads for street and swap in Hawk DTC30 for autocross and track.
You need race brake fluid too. For 5-6 times a year, Motul RBF600 in spring and something like Motul 5.1 after end of season should be fine.
At the same time, put in 70/30 water/coolant plus Water Wetter. I don't know where GVA is, but if it gets cold, go back to regular mix for winter.
I'm not clear on how important SS lines are. Most people say it's important. I personally didn't notice the difference.
PS springs plus Koni Sports is a good plan. If you can do the work yourself, I'd say M3 rear subframe bushings too. If you can't do the work yourself, I guess it's too expensive.
You should probably also get a E92 M3 front rollbar. Most people think it helps. And for $65
this thing is a no-brainer.
That's all you really need. If there's money left, spend it on track days.
...adding: I forgot to mention
titanium shims for the front brakes.