I think there are several layers to your question. You make a 2002 go pretty fast. It's a function of money and engineering. As with any car, major modifications usually start a chain of other mods to keep up (more hp means you need better brakes, etc). If that blows your dress up, then go for it. To me (and I own an S14 powered car), doing too much to these cars takes them out of character. For every engine choice other than an M10, there is a tradeoff (s14's vibrate, sixes weigh more, etc.). If you are just looking for performance, you have better choices for 20k. E30 M3's, E36 M3's, low mileage 944 turbos, etc.. If you are smitten with 2002's perhaps there is no other real choice for you. You will figure it out. There are a lot of resources here if you get more specific about what you want to build. All I can tell you is that I don't own either of the 02's for performance reasons and they perform pretty well for what they are.