Look for a 2000 S - 2003S with the lowest miles possible.
look into hiring an auto broker who probably has access to the Manheim
Porsche dealer auctions (not open to the public).
If you will be out of cash after $25K I would suggest making sure it comes
with HID or "Litronics" and 18 wheels. These two options can easily cost $3,000.
The option I like most on my Boxster is the premium audio package.
Its really the only convertible I've ridden in that sound excellent in with the top down.
Some people who are warm weather wimps think heated seats are a must have.
I thik an aero kit is a must have (GT3 front bumper and side skirting make all the difference in the word). $1,700 not including paint, factory parts).
here's a nice one with GT3 front bumper, side skirting and 18" Carrera 5 spokes
Here's a stock box with out HID (see the orange on the headlights?) 17" wheels and no aero. A big difference in looks for $5k in improvements.