Use the motivation to own a Porsche to complete school and aim high when getting a job.
I got a 944 (cheap) when I was 16, now I have that built up as a race car and my daily is a 987. I set a goal that my next car would be a Boxster and low and behold it was. Within 5 years (I'll be 28 or so) I want to own a GT3. I also want to build a Boxster Spec as well. These things are what make my life worth living, therefore I have motivation to excel at work and make lots of $$$$$$$$.
My suggestion would be to start out with a cheaper Porsche and work your way up. If you jump in to deep to begin with the sticker shock when parts break might be too much. Simple things like maintenance items get more expensive as you go to 911's and especially turbos. Boxsters are common enough that parts are available and affordable as far as Porsche parts go (10x normal cars).
Drive what you love love what you drive.
