It sounds like you have the 1.8l sohc engine, so it's going to be a little tougher.
Over the sea here they even made a 150hp sohc in the second generation neon. It's going to take a good amount of money to get 180hp.
This is a dynograph of a sohc with that much power. Neons have something like a 15% drivetrain loss, so it's showing how much power after that loss.
It is a 2.0l magnum sohc
The magnum engine has a better camshaft, intake manifold, more agressive programming, cylinder head with much improved exhaust ports and exhaust from the cylinder head to the tail pipe/muffler.
In this dyno it has an even better throttle body, intake manifold, pcm, header, exhaust, added are also an underdrive crank pulley and cold air intake.
For the 140 whp run, that was with the camshaft from a 2001 magnum engine. For the 155 whp run that is with the crane #14 camshaft.
For you to come close to this setup, it will easily cost $2500 USD before shipping for you to duplicate, and that is with still using your 1.8l block/pistons/rods/everything from the head gasket down to the oil pan.
As you can see, that's a lot of money for 180hp when you can spend about the same on a turbo kit and have much more potential and torque!