Got your PM. Answered.

Like I said in the PM, the S2000 is fitting if you're a hardcore trackster... it's like a big go-kart... and it bites like one if you push over the edge... but for a daily driver, I'd take an S15 (make sure the conversion is absolutely foolproof... have it done at a reputable shop or have it checked by a good mechanic). An S15 is more spacious, more civil, and has more low-down torque (in turbo form) for easy-to-access highway performance.

And there are tons of mods available for Nissan turbo motors.