Get a 2002 or later model - they got a number of improvements over the
earlier cars, notably 20 more horsepower and a 3.6l engine (up from 3.4l),
more chassis stiffness, some cosmetic changes in the headlights to
differentiate the car a little more from the Boxster. The 2002+ cars are
pretty strong - 0-60 mph in under five seconds, 1/4 mile in the mid to low
13 seconds, top speed 177, .90+g on the skidpad with stock suspension and
right at 1.0g with sport suspension.

Some cars have had rear main seal leaks (my 2002 did), but my two or three
drop per week leak was cured by a redesigned seal. Look into the specific
car's maintenance history - if it has a recurring RMS problem you might want
to find another. The RMS is about the only somewhat common gripe I've heard,
it's not all that widespread and generally fixed by the new seal.

Any car you choose should be taken to a Porsche specialist for a thorough
pre-purchase inspection before sugning on the dotted line.

Try

www.rennlist.com

they have forums devoted to specific Porsche models and also tech areas.