A nitrous kit is the only thing you can really do to that car to get any real gains.
No. With an intake you will not see any gains, I would be suprised to see +1hp on the dyno. But this would be my suggestion. Intake and an exhaunst, then an NX basic wet kit. Get a cheap intake, because the only advantage you will see fromt hat intake, is somthing to drill that NX nozle into
Also, yes, if the work is done right, you can out perform a stock turbo eclipse... but whars the point? I can buy one with a 4G63 and run 13's all day with a boost controller and some bolt ons. I am also told by many turboing a 420a motor is worthless because you will run into all kinds of problems and you might hit high 13's if you are luckey.