I agree with the others. There are a lot of Boxsters out there and there is no reason to settle on one that may have issues. You obviously know what your doing getting a PPI.
I agree with 10/10th that the glove box and glass rear window of the 2003 and 2004 Boxsters nice to have. The earlier models can be retrofitted with the 2003/04 tops or aftermarket glass tops are available. The glove box can't be retrofitted.... I looked into it.
I don't agree with 10/10th opnion on the looks and fit and finish. Looks are subjective. I prefer the simpler lines of the earlier years. And, I have never heard that fit and finish got better over the years. That said, If I was in the market for another Boxster I would look for a 2004 550 anniversary edition.
http://press.porsche.com/archive/products/press_kits/press_kits_2004/PDF/new/1-6_Spyder_Release.pdf
Take your time and enjoy the hunt. The right one is out there.