hi im the slowmotion guy. Ive had quite a few neons and i think i could help steer you in a good direction if you wanted to. first off im asuming that your car is a standard. Youre stock transmission is just fine it will bolt up to any 2.4L dodge motor(caravan, stratus, PT crusier, SRT-4) the best of the 2.4L is the PT cruiser because its got a newer design on a few parts of the motor but an older engine is good too. there is a multitude of ways for you to go. All motor, boost, or nitrous. take a stock botom end 2.4L remove the balancer shafts and put on a P&P head with some crane 18s for cams with normal bolt-ons and you can see around 170-180 hp and 160-170tq. go boost you can pick up SRT4 turbo manifold and turbo around $350 used SRT FMIC and some fuel system stuff and make 220-240hp on a stock 2.4L. and well nitrous speaks for itself.
either way stop by our shop on westerville road and i could give you more info on it or advice
btw another good sourse of infor is www.neons.org