I gotta go with others here and say the best bang for the buck for real performance gains are a good set of tires and some driver training. Most engine mods on these cars result in zero improvement in lap times so it's just money down the rat hole in terms of useable performance gains.
The 986/987 is a formidable sports car and in the hands of a skilled driver can outrun almost anything on an Auto-x course or technical racetrack. Here in So Cal a few showroom stock base Boxters regularly outrun everyone except fully stripped and modified race cars. Last week they beat all the 987 S, Cayman S, 997's, GT3's, Twin turbo's, etc. Not too bad for 217hp and a good set of street tires.
