My opinion would be that porting the intake manifold has a poor hp/$ ratio unless you have a very modified engine. Big throttle bodies mostly just trick you into thinking you gained power. Pushing on the pedal 15%, allows 25% airflow. At 75% pedal, you might get 100% airflow. That's great until you push the pedal down 100% and still only get 100% airflow. If your fully open TB was not a significant restriction for your engine demands, then all you do is make the car feel faster at part throttle. If you go too big, the throttle will be hard to modulate at low speeds. A more aggressive cam can have a good hp/$ ratio. If you are willing to trade idle quality and emissions for high RPM power, cams are a good choice. If you gain power at high RPM, you will usually lose some at low RPM. If you choose a conservative cam, you often don't notice any loss down low. It is just a moderate gain everywhere that counts. Cams are expensive though and often require heavier springs. Installing springs would generally mean removal of the head. As long as you had the head off, you should probably get a valve job since your engine probably has a some miles on it. It starts to add up quickly and the hp/$ ratio gets worse.

Corbin
'97 GSX dressed like a '95 ESi