Being an owner of a 01 GTS w/6-speed, I can say it will take a bit to nail down driving a car with a manual transmission. It took me about a month or so of regular driving before I managed to drive the thing without stalling out in my commute to college and back.
Also, while the later model years had fewer problems (?) the early models are the ones you want if you truly want to grab all 180 HP. I heard from someone before that the early models had a higher redline (8200RPM instead of the reduced 7600RPM in later years), but due to the tight spacing of the shifts, some people would end up blowing their engines and transmissions from improper shifting, hence the lowered redline and such (though they did try and later undo this with the 04/05 models). Plus, the early models had a throttle cable instead of drive-by-wire (less delay when putting the throttle down).
In any case, I would try aiming for a 2000-2002 GTS if you crave performance over appearance. Plus, as an added bonus, if you can drive one of them with the 6-speed, you'll pretty well be trained to drive anything with a stick shift in it. :P