My little experience
When I bought my first IWC I had the same dilemma.
I entered into the AD and asked for the Portoguese chrono, I just couldn't take my eyes off of it.
The shop assistant, probably because I aroused some tenderness to her, wanted me to try the flieger too.
It took few seconds to me to choose between the two and so I decided for the Portoguese. Later on, I bought the flieger too but that's another story.
The flieger is gorgeous but Portoguese chrono is probably a better start since it has everything to become your one and only IWC/watch or the premise for a great start in the world of watchmaking.
My little and humble experience.
Best wishes for your graduation.
Regards,
roberto