stibox,
I agree with Topless, good tires and upgraded suspension.
The Boxster is very different than the STI, IMHO of course.
We have an 02S that can eat up a $5000 Fabspeed mod car on the track - why you ask...because we have the suspension and the tires to run faster corners and brake later
Also, I agree with the 996 engine swap for more power...check on tholyoak's postings about Boxster engine swaps...IMHO, if RUF does it...it must mean something.
Take care,
Ed