Need advice on next purchase

[C's 94 InTeGrA]

Ok i got myself the iceman cold air intake, plugs and wires now i want something that would make a huge difference on horsepower and that u can feel a difference.. i waas thinking of..
1. Throttle body
2. intake manifold
3.fuelrail/regulator/injectors
or anything anyone else can think of..

Thanks